Paging related methods and apparatus

ABSTRACT

Efficient paging in a communications system including macro and small cell base stations is described. A macro cell base station receives, from a network node, a request to page a UE and determines a set of base stations including one or more small cell base stations, which are to attempt to page the UE. The macro cell base station communicates the paging request to the selected one or more small cell base stations. A small cell base station, using unlicensed spectrum, may fail in its paging attempt due to current unavailability of the unlicensed spectrum (LBT fails to clear) resulting in no paging signal transmitted; the reason for failure is communicated from the small cell base station to the macro cell base station via a paging response message. The macro cell base station in turn communicates a paging response message to the network node communicating the reason for failure.

RELATED APPLICATIONS

The present application is a Continuation-in-Part of U.S. patentapplication Ser. No. 16/270,513 filed on Feb. 7, 2019 and claims thebenefit of U.S. Provisional Application Ser. No. 62/737,014 filed Sep.26, 2018 and U.S. Provisional Application Ser. No. 62/753,642 filed Oct.31, 2018 which are hereby expressly incorporated by reference in theirentirety.

FIELD

The present application relates to communications methods and apparatus,and more particularly, to paging related methods and apparatus in acommunications system including macro and small cell base stations.

BACKGROUND

Wireless communications systems are starting to make wider use ofunlicensed spectrum. However, with the use of unlicensed spectrum, thereis the uncertainty that the physical medium for transmission may not beavailable at the desired time of the intended wireless signaltransmission. With paging operations in licensed spectrum, pagingsignaling from a base station can be scheduled, and it may be assumedthat a paging request from a core node to a base station to page a UE iscarried out. However, with unlicensed spectrum, the base station may beunable to transmit a core node requested page due to currentunavailability of the unlicensed spectrum in the vicinity of the basestation. This creates uncertainty at the core node requesting the page,since the core node does not know the reason that its page request hasnot been responded to. The core node can not efficiently make pagingdecisions, e.g., regarding expanding the page range, if the core nodedoes not know the reason for the paging failure.

Wireless communications systems have been increasing the use of smallcell base stations to augment the wireless coverage area, e.g., toprovide coverage in dead zones within a macro cell base station'scoverage area and/or to expand the coverage area beyond the outermostregions of the macro cell coverage, e.g., to fill in gaps betweenadjacent macro cells. Such a densification implies the number of smallcells in a wireless communications system can be, and sometimes is, muchlarger, than the number of macro cells in the communications system. Asthe total number of small cells to manage with regard to paging (a givenUE) becomes large, it becomes inefficient for the core network node, totry to individually manage and directly communicate with each small cellbase station with regard to, for a given UE, sending paging requests andreceiving paging responses.

Based on the above discussion there is a need for new methods andapparatus for supporting paging and particularly paging incommunications systems including small cell base stations which useunlicensed spectrum.

SUMMARY

Methods and apparatus for efficient paging in a communications system,e.g., a communications system including macro cell base stations andsmall cell base stations are described. Various features are directed toefficient paging in unlicensed spectrum, with various aspects relatingto one or more of: macro cell base station paging control and managementfeatures, macro cell base station/small base station features, basestation/core network node features, access and mobility function (AMF)node features and/or signaling features.

Some features are directed to a base station, e.g., a macro cell basestation, which has received, from a network node (e.g., an AMF), apaging request to page a particular UE, determining a set of basestations, e.g., including one or more small cell base stations usingeither unlicensed or licensed spectrum, which are to attempt to page theparticular UE. The determination is, e.g., based on one or more of: i)historical cell information if submitted by the UE; ii) UE mobilitypattern information as derived at the macro cell base station; iii)historical signal measurement reports communicated by the UE; iv)channel quality information feedback regarding potential target smallcell base stations communicated by the UE (e.g. in measurement reports),v) physical downlink control channel load on a physical downlink controlchannel (PDCCH) with regard to paging, vi) a received signal strength ofa signal transmitted by the macro base station as reported by the UE,vii) number of UEs requiring paging at that instant of time, vii) numberof small cells “under” (i.e. with varying degrees of overlap) a coveragearea of the macro base station, or viii) radio network planning data. Atdifferent times, the macro cell base station may, and sometimes does,determine a different group of small cell base stations, which are toattempt to page the same UE, e.g., depending upon current conditions.

Some features are directed to a macro cell base station interacting withand/or controlling small cell base stations which have coverage areaswhich partially or fully overlap the coverage area of the macro cellbase station. Some features are directed to a paging request message,e.g., a paging request message from the macro cell base station to asmall cell base station, which has been determined by the macro cellbase station to be one of the selected base stations to attempt to pagea UE, while other features are directed to novel paging responsemessages, e.g., a novel paging response message from the small cell basestation to the macro cell base station. The paging response messages, insome embodiments, include a paging failure response message, and in someembodiments, a paging success response message. The paging failureresponse message communicates in some, but not necessarily allembodiments, a failure cause code indicating a reason for pagingfailure. The failure indication may be, and sometimes does, depend onthe spectrum in which the page was attempted. For unlicensed spectrum apaging failure indication may be, and sometime is, one of the following:i) currently unavailable unlicensed spectrum (e.g., due to Listen BeforeTalk (LBT) not clearing), or ii) no response received from UE inresponse to transmitted paging signal in unlicensed spectrum.

The macro cell base station may, and sometimes does, receive pagingresponse messages from one or more small cell base stations. The macrocell base station uses the information included in the received pagingresponse message, in determining an overall paging attempt result, e.g.,aggregating information and making an overall determination with regardto paging success or failure from the perspective of the macro cell basestation. The macro cell base station generates and sends a pagingresponse message, communicating the overall paging attempt result to thenetwork node, e.g., an AMF node. The paging response message sent to thenetwork node may, and sometimes does, include information indicating thereason or reasons for the paging attempt failure.

Different embodiments may include and support different features anddevices. Accordingly, while various features and/or devices arediscussed they are not necessary for all embodiments.

An exemplary communications method, in accordance with some embodiments,comprises: receiving, at a first base station, a paging request to pagea first UE device; determining, at the first base station, a first setof base stations which are to attempt to page the first UE device, saidfirst set of base stations including a small cell base station; sending,from the first base station, a paging request message to the small cellbase station in said first set of base stations, said paging requestmessage requesting paging of the first UE device; and receiving, at thefirst base station, a paging response message from the small cell basestation, said paging response message indicating one of: i) an attemptat the small cell base station to page the first UE device wassuccessful or ii) an attempt at the small cell base station to page thefirst UE device was unsuccessful. An exemplary communications system, inaccordance with some embodiments, comprises: a first base stationincluding: a first processor configured to: operate the first basestation to receive a paging request to page a first UE device; determinea first set of base stations which are to attempt to page the first UEdevice, said first set of base stations including a small cell basestation; operate the first base station to send a paging request messageto the small cell base station in said first set of base stations, saidpaging request message requesting paging of the first UE device; andoperate the first base station to receive a paging response message fromthe small cell base station, said paging response message indicating oneof: i) an attempt at the small cell base station to page the first UEdevice was successful or ii) an attempt at the small cell base stationto page the first UE device was unsuccessful.

While various features discussed in the summary are used in someembodiments it should be appreciated that not all features are requiredor necessary for all embodiments and the mention of features in thesummary should in no way be interpreted as implying that the feature isnecessary or critical for all embodiments.

Numerous additional features and embodiments are discussed in thedetailed description which follows.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a drawing of an exemplary communications system in accordancewith an exemplary embodiment.

FIG. 2A is a first part of a flowchart of an exemplary method ofoperating a communications system including at least one base station,e.g., a gNB or ng-eNB, that uses at least some unlicensed spectrum andtransmits paging signals in the unlicensed spectrum, in accordance withan exemplary embodiment.

FIG. 2B is a second part of a flowchart of an exemplary method ofoperating a communications system including at least one base station,e.g., a gNB or ng-eNB, that uses at least some unlicensed spectrum andtransmits paging signals in the unlicensed spectrum, in accordance withan exemplary embodiment.

FIG. 2C is a third part of a flowchart of an exemplary method ofoperating a communications system including at least one base station,e.g., a gNB or ng-eNB, that uses at least some unlicensed spectrum andtransmits paging signals in the unlicensed spectrum, in accordance withan exemplary embodiment.

FIG. 2D is a fourth part of a flowchart of an exemplary method ofoperating a communications system including at least one base station,e.g., a gNB or ng-eNB, that uses at least some unlicensed spectrum andtransmits paging signals in the unlicensed spectrum, in accordance withan exemplary embodiment.

FIG. 2 comprises the combination of FIG. 2A, FIG. 2B, FIG. 2C and FIG.2D.

FIG. 3 is a drawing of an exemplary base station, e.g., a gNB or ng-eNB,in accordance with an exemplary embodiment.

FIG. 4A is a first part of an exemplary assembly of components which maybe included in a base station implemented in accordance with anexemplary embodiment.

FIG. 4B is a second part of an exemplary assembly of components whichmay be included in a base station implemented in accordance with anexemplary embodiment.

FIG. 4C is a third part of an exemplary assembly of components which maybe included in a base station implemented in accordance with anexemplary embodiment.

FIG. 4 comprises the combination of FIG. 4A, FIG. 4B and FIG. 4C.

FIG. 5 is a drawing of an exemplary communications system using licensedand unlicensed spectrum in accordance with an exemplary embodiment.

FIG. 6 illustrates an exemplary paging request for paging a userequipment (UE) device being communicated from an access and mobilityfunction (AMF) to a primary node (PN) base station (e.g. a macro basestation) and exemplary paging requests for paging the UE beingcommunicated from the PN base station to secondary node (SN) basestations (e.g. a small cell base station) in accordance with anexemplary embodiment.

FIG. 7 illustrates exemplary paging attempts of the UE being performedat base stations concurrently using licensed and unlicensed spectrum.

FIG. 8 illustrates exemplary paging response messages including faultcode information being communicated from SN base stations to the PN basestation, and from the PN base station to the AMF device, in accordancewith an exemplary embodiment.

FIG. 9 illustrate an exemplary paging attempt in which the pagingattempt fails due to unavailable unlicensed spectrum in accordance withan exemplary embodiment.

FIG. 10 illustrate an exemplary paging attempt in which the pagingattempt fails due to no response from the UE device being paged inaccordance with an exemplary embodiment.

FIG. 11 illustrates an exemplary paging attempt in which the pagingattempt is a success in accordance with an exemplary embodiment.

FIG. 12 is a drawing of an exemplary user equipment (UE) deviceimplemented in accordance with an exemplary embodiment.

FIG. 13 is a drawing of an exemplary network node, e.g., an AMF,implemented in accordance with an exemplary embodiment.

FIG. 14A is a first part of an exemplary assembly of components whichmay be included in a network node, e.g., an AMF, implemented inaccordance with an exemplary embodiment.

FIG. 14B is a second part of an exemplary assembly of components whichmay be included in a network node, e.g., an AMF, implemented inaccordance with an exemplary embodiment.

FIG. 14 comprises the combination of FIG. 14A and FIG. 14B.

FIG. 15A is a first part of a flowchart of an exemplary method ofoperating a macro cell base station in accordance with an exemplaryembodiment, said exemplary method including paging related operations.

FIG. 15B is a second part of a flowchart of an exemplary method ofoperating a macro cell base station in accordance with an exemplaryembodiment, said exemplary method including paging related operations.

FIG. 15C is a third part of a flowchart of an exemplary method ofoperating a macro cell base station in accordance with an exemplaryembodiment, said exemplary method including paging related operations.

FIG. 15D is a fourth part of a flowchart of an exemplary method ofoperating a macro cell base station in accordance with an exemplaryembodiment, said exemplary method including paging related operations.

FIG. 15, comprising the combination of FIG. 15A, FIG. 15B, FIG. 15C andFIG. 15D.

FIG. 16 is a drawing of an exemplary communications system in accordancewith an exemplary embodiment.

FIG. 17 is a drawing which illustrates exemplary signaling and exemplarysteps performed in the system of FIG. 16 including an exemplary macrocell base station receiving a paging request to page a UE, determining aset of base stations including a group of small cell base stations whichare to attempt to page the UE, and sending a paging request to each ofthe small cell base stations in the group, in accordance with anexemplary embodiment.

FIG. 18, which is a continuation of FIG. 17, illustrates an example inwhich the macro base station is able to transmit a paging signal to pagethe UE; however, the small cell base stations are unable to transmit apaging signal because the unlicensed spectrum used by the small cellbase stations is unavailable.

FIG. 19, which is a continuation of FIG. 18, illustrates exemplarypaging response messages between the small cell base stations and themacro cell base station, and between the macro cell base station and theaccess and mobility function device, which indicate that the pagingattempt was unsuccessful and that intended paging messages were nottransmitted due to unavailability of unlicensed spectrum.

FIG. 20, which is a continuation of FIG. 17, illustrates an alternativeexample in which the macro base station and the small cell base stationsare able to transmit a paging signal to page the UE; and one of thesmall cell base stations detects a paging response from the UE beingpaged.

FIG. 21, which is a continuation of FIG. 20, illustrates a pagingfailure response message from a first small cell base station to themacro cell base station, a paging success response message from a secondsmall cell base station to the macro cell base station, and a pagingsuccess response message from the macro base station to the AMF inaccordance with an exemplary embodiment.

FIG. 22 is a drawing which illustrates exemplary signaling and exemplarysteps performed in the system of FIG. 16 including an exemplary macrocell base station receiving a paging request to page another UE,determining a set of base stations including a group of small cell basestations which are to attempt to page the another UE, and sending apaging request to each of the small cell base stations in the group, inaccordance with an exemplary embodiment.

FIG. 23, which is a continuation of FIG. 22, illustrates an example inwhich the macro base station and the small cell base station in thedetermined group are able to transmit a paging signal to page the UE;however, the UE does not respond to the paging signals, since the UE isnot in the coverage areas into which the paging signals weretransmitted.

FIG. 24, which is a continuation of FIG. 23, illustrates a pagingfailure response message from the small cell base station to the macrocell base station, and a paging failure response message from the macrobase station to the AMF, said paging failure response messagecommunicating that the paging attempt failure was due to no responsefrom the UE, in accordance with an exemplary embodiment.

FIG. 25 is a flowchart of an exemplary method of operating a small cellbase station, in accordance with an exemplary embodiment, said exemplarymethod including paging related operations.

FIG. 26 is a drawing of an exemplary macro cell base station inaccordance with an exemplary embodiment.

FIG. 27 is a drawing of an exemplary small cell base station inaccordance with an exemplary embodiment.

FIG. 28A is a first part of a drawing of an exemplary assembly ofcomponents which may be included in a macro cell base station inaccordance with an exemplary embodiment.

FIG. 28B is a second part of a drawing of an exemplary assembly ofcomponents which may be included in a macro cell base station inaccordance with an exemplary embodiment.

FIG. 28, comprising the combination of FIG. 28A and FIG. 28B.

FIG. 29A is a first part of a drawing of an exemplary assembly ofcomponents which may be included in a small cell base station inaccordance with an exemplary embodiment.

FIG. 29B is a second part of a drawing of an exemplary assembly ofcomponents which may be included in a small cell base station inaccordance with an exemplary embodiment.

FIG. 29 comprises the combination of FIG. 29A and FIG. 29B.

FIG. 30 is a drawing of an exemplary communications system in which boththe macro cell base stations and small cell base stations use unlicensedspectrum, in accordance with an exemplary embodiment.

FIG. 31 is a drawing of an exemplary communications system in which themacro cell base stations use licensed spectrum, some of the small cellbase stations use unlicensed spectrum and some of the small cell basestations use licensed spectrum, in accordance with an exemplaryembodiment.

FIG. 32 is a drawing of an exemplary paging response message inaccordance with some exemplary embodiments, e.g., some embodiments, inwhich both paging success and paging failure response messages aregenerated and transmitted.

FIG. 33 is a drawing of another exemplary paging response message inaccordance with some exemplary embodiments, e.g., some embodiments, inwhich paging failure response messages are generated and transmitted.

FIG. 34 is a drawing of another exemplary paging response message inaccordance with some exemplary embodiments, e.g., some embodiments, inwhich paging failure response messages are generated and transmitted, inresponse to a determination of unavailability of unlicensed spectrum.

DETAILED DESCRIPTION

FIG. 1 is a drawing of an exemplary communications system 100 inaccordance with an exemplary embodiment. Exemplary communications system100 includes an access and mobility function (AMF) device 102, aplurality of base stations (base station 1 104, e.g., gNB 1 or ng-eNB 1,base station 2 106, e.g., gNB 2 or ng-eNB 2, . . . , base station n 108,e.g., gNBn or ng-eNBn), and a plurality of user equipment (UE) devices(UE 1 110, UE 2 112, UE 3 114, UE 4 116, UE 5 118, UE 6 120, . . . , UEN 122). Each of the base stations (base station 1 104, base station 2106, . . . , base station n 108) has a corresponding wireless coveragearea (105, 107, . . . , 109), respectively. AMF 102 is coupled to basestation 1 104 via communications connection 124. AMF 102 is coupled tobase station 2 106 via communications connection 126. AMF 102 is coupledto base station n 108 via communications connection 128. The basestations (104, 106, . . . , 108) can, and sometimes do, use unlicensedspectrum, e.g. unlicensed spectrum using a first unlicensed carrier. Insome embodiments, at least some of the base stations (104, 106, . . . ,108) support communications over multiple different unlicensedspectrums. In some embodiments, at least some different base stations(104, 106, . . . , 108) use different unlicensed spectrum. In someembodiments, at least some of the base stations (104, 106, . . . , 108)use licensed spectrum. In some embodiments, at least some of the basestations (104, 106, . . . , 108) use licensed and unlicensed spectrum.

At least some of the UE devices (110, 112, 114, 116, 118, 120, . . . ,122) are mobile devices which may move throughout the communicationssystem 100. In the drawing of FIG. 1, UE 1 110 and UE 2 112 are shown tobe currently within the wireless coverage area 105 of base station 1104. UE 3 114 is shown to be currently outside the coverage areas (105,107, 109) of the base stations. UE 4 116 and UE 5 118 are shown to becurrently within the wireless coverage area 107 of base station 2 106.UE 6 120 and UE N 122 are shown to be currently within the wirelesscoverage area 109 of base station 3 108.

Due to pending downlink data (in UPF buffer) destined for a UE in idlemode (5GMM_IDLE), the AMF 102 generates and sends a paging request forpaging that particular UE to one or more of the base stations (104, 106,. . . 108). A base station (e.g., base station 104, 106, or 108), whichreceive the paging request from the AMF 102, determines if unlicensedspectrum intended to be used by the base station is currently available,and if the determination is that the unlicensed spectrum is available,the base station generates and transmits a paging signal to the UE inunlicensed spectrum. The UEs (110, 112, 114, 116, 118, 120, . . . 122)monitor for and detect paging signals in unlicensed spectrum. If thepaging attempt is unsuccessful, the base station generates and sends apaging response message to the AMF 102, e.g., a paging failure responsemessage. In various embodiments, the paging failure response messageincludes a failure cause code indicating the reason for the pagingfailure, e.g., the base station was unable to transmit the pagingrequest to the UE because the unlicensed spectrum was unavailable (e.g.,due to listen before talk (LBT) performed by the base station notclearing) or the UE did not respond to a transmitted paging requestwhich was transmitted by the base station in the unlicensed spectrum,e.g., because the UE was not in the coverage area of the base station orthe UE was powered down. The AMF 102 receives the paging failureresponse message, recovers the failure cause code, and implements apaging escalation strategy as a function of the recovered failure causecode.

FIG. 2, comprising the combination of FIG. 2A, FIG. 2B, FIG. 2C and FIG.2D, is a flowchart 200 of an exemplary method of operating acommunications system including at least one base station, e.g., a gNBor ng-eNB, that uses unlicensed spectrum in accordance with an exemplaryembodiment. Operation starts in step 202, in which the communicationssystem is powered on and initialized, and proceeds to step 204.

In step 204 a network node, e.g., an access and mobility managementfunction (AMF), used to control paging of user equipment (UE) devices,generates a first paging request, said first paging request being arequest to page a first UE device. Operation proceeds from step 204 tostep 206. In step 206 the network node sends the generated first pagingrequest to a first base station, e.g., a gNB or an ng-eNB, said firstbase station using unlicensed spectrum. Operation proceeds from step 206to step 208.

In step 208, the first base station receives said first paging requestfrom said network node, e.g., an AMF, used to control paging of UEdevices, said first paging request being a request to page said first UEdevice. In some embodiments, the first paging request is a class 1 N2-APPaging_U message. Operation proceeds from step 208 to step 210.

In step 210 the first base station performs a paging operation to pagethe first UE device using unlicensed spectrum. Step 210 includes steps211, 212, 213, 214, 215, 216, 220 and 224.

In step 211, the first base station sets the value of the variabletransmission attempt to 1. Operation proceeds from step 211 to step 212.In step 212 the first base station performs a channel sensing conditionoperation, e.g., a listen before talk (LBT) operation, to determine ifthe first base station can transmit a paging signal to the first UEdevice using said unlicensed spectrum. Operation proceeds from step 212to step 213. In step 213, if the channel sensing condition operation hasdetermined that the first base station can transmit the paging signal tothe first UE device using the unlicensed spectrum, then operationproceeds from step 213 to step 216 and step 220. In step 216 the firstbase station transmits a paging signal to said first UE device usingsaid unlicensed spectrum. In some embodiments, step 216 includes step218, in which the first base station transmits a paging message to saidfirst UE device N number of time and/or repetitively during apredetermined time interval T. In step 220 the first base stationmonitors to detect a response from said first UE device in response tothe transmitted paging signal of step 216. Step 220 may, and sometimesdoes, include step 222, in which the first base station receives aresponse from the first UE device in response to the transmitted pagingsignal of step 216.

Alternatively, in step 213, if the channel sensing condition operationhas determined that the first base station can not transmit the pagingsignal to the first UE device using the unlicensed spectrum, thenoperation proceeds from step 213 to step 214, in which the first basestation determines if the configurable maximum number of transmissionattempts has been reached. For example, the configurable maximum numberof transmission attempts has been previously configured, e.g., set, to apredetermined integer, e.g., three. In step 214, the first base stationcompares the current value of the variable transmission attempt to themaximum number of transmission attempts, and controls operation as afunction of the determination. If the current value of the transmissionattempt does not equal the maximum number of transmission attempts, thenoperation proceeds from step 214 to step 215, in which the first basestation increments the current value of the variable transmissionattempt. Operation proceeds from step 215 to step 212, in which anotheriteration of the channel sensing condition operation, e.g., anotheriteration of LBT, is performed. Alternatively, in step 214, if thecurrent value of the transmission attempt equals the maximum number oftransmission attempts, then operation proceeds from step 214 to step224. In step 224, the first base station is controlled to refrain fromtransmitting a paging signal to said first UE device using saidunlicensed spectrum.

Operation proceeds from step 210, via connecting node A 226, to step228, in which the first base station determines whether the pagingoperation was successful or unsuccessful. Step 228 includes steps 230,236, 238, 240, 242, 244, and 246. In step 230 the first base stationdetermines if a paging signal was transmitted to said first UE device aspart of the paging operation. During some iterations of step 230, thefirst base station determines in step 232 that a paging signal was nottransmitted to said first UE device as part of said paging operation.During some iterations of step 230, the first base station determines instep 234, that a paging signal was transmitted to said first UE deviceas part of said paging operation. Operation proceeds from step 230 tostep 236. In step 236, if the determination is that the paging signalwas not transmitted to the first UE device as part of the pagingoperation, then operation proceeds from step 236 to step 238 in whichthe first base station determines that the paging operation was notsuccessful. However, in step 236 if the determination is that the pagingsignal was transmitted to the first UE device as part of the pagingoperation, then, operation proceeds from step 236 to step 240, in whichthe first base station determines if a response was received by thefirst base station in response to the paging signal transmitted to thefirst UE device. Operation proceeds from step 240 to step 242. In step242, if the determination is that a response signal was received by thefirst base station in response to the paging signal transmitted to thefirst UE device, then operation proceeds from step 242 to step 244, inwhich the first base station determines that the paging operation wassuccessful. However, in step 242, if the determination is that aresponse signal was not received by the first base station in responseto the paging signal transmitted to the first UE device, then operationproceeds from step 242 to step 246, in which the first base stationdetermines that the paging operation was not successful.

Operation proceeds from step 228, via connecting node B 248, to step250. In step 250, if the determination is that the paging operation wasunsuccessful, then operation proceeds from step 250 to step 252. In step250, if the determination is that the paging operation was successfulthen operation proceeds from step 250 to step 254.

In step 252 the first base station communicates a paging response, e.g.,a paging failure response message, to the network node in response tothe first paging request, said paging response indicating that thepaging operation was unsuccessful. In some embodiments, step 252includes step 256.

In step 256 the first base station transmits a paging response, e.g., apaging response signal, to the first network node that includes afailure cause code indicating the reason that the paging operationfailed. In some embodiments, the paging response signal is aN2-AP:PAGING_U RESPONSE message including a failure cause code. In someembodiments, step 256 includes step 258 and 260, and one of steps 258and 260 is performed during an iteration of step 256.

In step 258 the first base station transmits a paging response to thefirst network node that includes a failure cause code indicating thereason that the paging operation failed was due to a failure by thefirst base station to transmit the paging signal to the first UE device,e.g., in response to step 238 determining that the paging operation wasnot successful. In step 260 the first base station transmits a pagingresponse to the first network node that includes a failure cause codeindicating the reason that the paging operation failed was due to afailure to receive a reply from the first UE device, e.g., in responseto step 246 determining that the paging operation was not successful.

Returning to step 254, in step 254 the first base station performs oneof: i) proceeding with normal operation without sending a pagingresponse message to the network node in response to the said firstpaging request or ii) sending a paging success response message to thenetwork node in response to the first paging request.

Operation proceeds from step 252, via connecting node C 262, to step264. In some embodiments, e.g. an embodiment in which the first basestation may, and sometimes does, send paging response success messages,operation proceed from step 254, via connecting node C 262, to step 264.In step 264 the network node monitors for a paging response message,e.g., a paging failure response message or a paging success responsemessage, from the first base station, which was sent in response to thefirst paging request message. Step 264 may, and sometimes does, includestep 266, in which the network node receives a paging response message.Operation proceeds from step 266 to step 268.

In step 268, the network node determines if the paging response messageis a paging failure response message or a paging success responsemessage. If the paging response message is a paging success responsemessage, then operation proceeds from step 268 to step 272, in which thenetwork node determines that the paging of the first UE device has beensuccessful. However, if the paging response message is a paging failureresponse message, then operation proceeds from step 268, to step 270, inwhich the network node implements a paging escalation strategy as afunction of the failure cause code in the received paging responsemessage. Step 270 includes steps 274, 276, 278, 280 and 284. In step274, if the communicated failure cause code indicates that the pagingsignal was transmitted but no response was received, then operationproceeds from step 274 to step 276; otherwise, operation proceeds fromstep 274 to step 278.

In step 276, the network node determines to change the paging area ofthe first UE device. Operation proceeds from step 276 to step 280, inwhich the network node sends a paging request message to a second basestation requesting the second base station to page the first UE device.In various embodiments, the area covered by the second base station isone of: partially non-overlapping with the area covered by the firstbase station or ii) fully non-overlapping with the area covered by thefirst base station.

In step 278 the network node determines if the communicated failurecause code indicates that the first base station was unable to transmitan intended paging signal because of non-availability of unlicensedspectrum (non-availability of unlicensed carrier, e.g., the LBT did notclear), and the attempted failed paging attempt was an initial attemptof paging corresponding to the first paging request, e.g., a firstattempt to page the first UE in unlicensed spectrum intended to be usedby the first base station. If the determination is that the first basestation was unable to transmit an intended paging signal to the first UEbecause of non-availability of unlicensed spectrum, and the attemptedfailed paging attempt was an initial attempt of paging corresponding tothe first paging request, then operation proceeds from step 278 to step284, in which the network node re-sends the first paging request to thefirst base station. Operation proceeds from step 284, via connectingnode D 286, to step 208, in which the first base station receives thefirst paging request.

If the determination of step 278 is that the first base station wasunable to transmit an intended paging signal because of non-availabilityof unlicensed spectrum, but the attempted failed paging attempt was notan initial attempt of paging corresponding to the first paging request,then operation proceeds from step 278 to step 276, in which the networknode determines to change the first paging area of the first UE device.Operation proceeds from step 276 to step 280, in the network node sendsa paging request to a second base station requesting the second basestation to page the first UE device.

In some other embodiments, different approaches are used for expandingthe paging coverage area based on received failure fault codes. Forexample in one embodiment, if the network node receives a failure faultcode from a first base station indicating that the first base stationsuccessfully transmitted the paging request to the first UE but thefirst UE did not respond, then the network node refrains from sendingadditional paging requests to the first base station to page the firstUE, but sends a paging request to a different base station. e.g., asecond base station, requesting the second base station to page thefirst UE. However, if the network node receives a failure fault codefrom the first base station indicating that the first base station wasunable to transmit the page because the unlicensed spectrum wasunavailable (e.g., LBT did not clear), then the network node sends apaging request to both the first base station and the second basestation requesting that the first UE be paged.

FIG. 3 is a drawing of an exemplary base station 300, e.g., a gNB orng-eNB, in accordance with an exemplary embodiment. In some embodiments,exemplary base station 300 of FIG. 3 implements steps of the exemplarymethod of flowchart 200 of FIG. 2. Base station 300 is, e.g., any ofbase stations (base station 1 104, base station 2 106, . . . , basestation n 108) of FIG. 1 or any of the base stations (504, 506, 508,510, 512, 514) of FIG. 5.

Base station 300 includes a processor 302, e.g., a CPU, wirelessinterface 304, a network interface 306, e.g., a wired or opticalinterface, an assembly of hardware components 308, e.g., an assembly ofcircuits, and memory 310 coupled together via a bus 311 over which thevarious elements may interchange data and information.

Network interface 306 includes a receiver 316 and a transmitter 318.Network interface 306 to coupled to network nodes, e.g., via a backhaulnetwork and/or the Internet. Wireless interface 304 includes a wirelessreceiver 312 and a wireless transmitter 314. The base station 300receives signals from network devices, e.g., an AMF, via networkreceiver 316. An exemplary received signal, which is received viareceiver 316, is a first paging request signal, which was sent from anetwork node, e.g., an AMF, to control paging of UE devices, said firstpaging request being a request to page a first UE device, e.g., arequest to page a first UE device using unlicensed spectrum. Anexemplary signal transmitted via transmitter 318 is a paging responsesignal, e.g., a paging response failure message including a failure codecause indicator, or a paging success response message, said pagingresponse signal being sent to a network node, e.g., an AMF, in responseto a previously received paging request.

Wireless receiver 312 is coupled to a receive antenna 313 via which thebase station 300 can receive wireless signals, e.g., wireless signalsfrom UE devices. Wireless transmitter 314 is coupled to a transmitantenna 315 via which the base station 300 can transmit wireless signalsto UE devices. Exemplary transmitted wireless signals include a unicastpaging signal to a first UE device and a multicast or broadcastsecondary carrier monitoring control signal to UE devices, said UEdevices including said first UE device. Exemplary received wirelesssignals include a paging response signal from the first UE device.

Memory 310 includes a control routine 320, e.g., for controlling basicfunctions of the base station, an assembly of components 322, e.g., anassembly of software components, and data/information 324.Data/information 324 includes generated secondary carrier monitoringcontrol signal 350 including information 352 identifying the secondarycarrier, e.g., a secondary unlicensed spectrum carrier, and a secondarycarrier enable/disable flag 354, e.g., a bit field in the messagecommunicating whether the UEs should or should not monitor for pagingsignals using the secondary carrier. Data/information further includesunlicensed spectrum information 370 and licensed spectrum information371. Unlicensed spectrum information 370 includes informationcorresponding to one or more portions of unlicensed spectrum, which maybe, and sometimes are, used for transmitting paging signals to UEdevices. Unlicensed spectrum information 370 includes carrier 1, e.g., aprimary carrier, information, carrier 2 information 374, . . . , carrierM information 376. Data/information 324 further includes a predeterminedwait time value 368 for a paging response from a UE to which a pagingsignal has been transmitted, which represented the time the base station300 is to wait, e.g., after transmitting a paging signal, for aresponse, before declaring the paging attempt as a failure do to noresponse from the UE. Data/information 324 further includes information378 mapping paging failures to failure codes. Information 378 includes afailure to transmit a paging signal to the UE 380 which maps to code 1382, e.g., represented by bit pattern 01. Information 378 furtherincludes a failure to receive a response from a UE to which a pagingsignal has been transmitted 384 which maps to code 2 386, e.g.,represented by bit pattern 10.

Data/information 324 further includes a received first paging request356 from a network node, e.g. a AMF node, channel sensing result(s) 360,configurable maximum number of transmission attempts 361, e.g., aninteger value greater than or equal to one indicating the maximum numberof attempts at LBT to be performed before giving up with an attemptedpaging signal transmission to the UE in unlicensed spectrum, generatedpaging signal(s) 362, received paging response signal(s) from UE(s) 364,paging operation success/failure information for a paging attempt 388,and a generated paging response message 398 to be sent to the networknode which sent the first paging request. Received paging request fromthe network node 356 includes UE ID information 358 identifying the UEdevice which is to be paged by the base station. Paging operationsuccess/fail information for a paging attempt 388 includes failureinformation 390 and/or success information 396. Failure informationincludes carrier information 392, e.g., information identifying whichcarrier(s) corresponded to the paging failure, and reason information394, e.g., information identifying the reason for the paging failure oneach of the carriers on which paging was attempted. Success information395 includes carrier information 397 identifying the carrier on whichthe successful paging signal was transmitted. Generated paging responsemessage 398, may, and sometimes, does include paging failure codeinformation 399, e.g., a failure code identifying the reason for thepaging failure. In some embodiments, in paging was attempted and failedon multiple carriers, the generated paging response message includes afailure code for each of the carriers on which the paging attemptfailed. In some embodiments, if the paging attempt was successful thegenerated paging response message 398 includes information identifyingthe carrier used for the successful page.

FIG. 4, comprising the combination of FIG. 4A, FIG. 4B and FIG. 4C, is adrawing of an exemplary assembly of components 400, comprising thecombination of Part A 401, Part B 403 and Part C 405, in accordance withan exemplary embodiment. Exemplary assembly of components 400 which maybe included in a base station, e.g., a gNB or an ng-eNB, such as theexemplary base station 300, e.g., a gNB or ng-eNB, of FIG. 3, andimplement steps of an exemplary method, e.g., steps of the method of theflowchart 200 of FIG. 2.

Assembly of components 400 can be, and in some embodiments is, used inbase station 300, e.g., a gNB or ng-eNB, of FIG. 3, base station 1 104of FIG. 1, base station 2 106 of FIG. 1 and/or base station n 108 ofFIG. 1. The components in the assembly of components 400 can, and insome embodiments are, implemented fully in hardware within the processor302, e.g., as individual circuits. The components in the assembly ofcomponents 400 can, and in some embodiments are, implemented fully inhardware within the assembly of components 308, e.g., as individualcircuits corresponding to the different components. In other embodimentssome of the components are implemented, e.g., as circuits, within theprocessor 302 with other components being implemented, e.g., as circuitswithin assembly of components 308, external to and coupled to theprocessor 302. As should be appreciated the level of integration ofcomponents on the processor and/or with some components being externalto the processor may be one of design choice. Alternatively, rather thanbeing implemented as circuits, all or some of the components may beimplemented in software and stored in the memory 310 of the base station300, e.g., a gNB or ng-eNB, with the components controlling operation ofthe base station to implement the functions corresponding to thecomponents when the components are executed by a processor, e.g.,processor 302. In some such embodiments, the assembly of components 400is included in the memory 310 as assembly of components 322. In stillother embodiments, various components in assembly of components 400 areimplemented as a combination of hardware and software, e.g., withanother circuit external to the processor 302 providing input to theprocessor 302 which then under software control operates to perform aportion of a component's function. While processor 302 is shown in theFIG. 3 embodiment as a single processor, e.g., computer, it should beappreciated that the processor 302 may be implemented as one or moreprocessors, e.g., computers.

When implemented in software the components include code, which whenexecuted by the processor 302, configure the processor 302 to implementthe function corresponding to the component. In embodiments where theassembly of components 400 is stored in the memory 310, the memory 310is a computer program product comprising a computer readable mediumcomprising code, e.g., individual code for each component, for causingat least one computer, e.g., processor 302, to implement the functionsto which the components correspond.

Completely hardware based or completely software based components may beused. However, it should be appreciated that any combination of softwareand hardware, e.g., circuit implemented components may be used toimplement the functions. As should be appreciated, the componentsillustrated in FIG. 4 control and/or configure the base station 300, orelements therein such as the processor 302, to perform the functions ofcorresponding steps illustrated and/or described in the method of one ormore of the flowcharts, signaling diagrams and/or described with respectto any of the Figures. Thus the assembly of components 400 includesvarious components that perform functions of corresponding one or moredescribed and/or illustrated steps of an exemplary method, e.g., stepsof the method of flowchart 200 of FIG. 2 and/or described or shown withrespect to any of the other figures.

Assembly of components 400 includes a component 404 configured toreceive, at the base station, a first paging request form a networknode, e.g., an AMF, used to control paging of UE devices, said firstpaging request being a request to page a first UE device, and acomponent 410 configured to perform a paging operation to page the firstUE device using unlicensed spectrum

Component 410 includes a component 411 configured to set the variabletransmission attempt equal to 1; a component 412 configured to perform achannel sensing operation, e.g., a LBT operation, to determine if thebase station can transmit a paging signal to the first UE device usingsaid unlicensed spectrum, a component 413 configured to controloperation as a function of the determination as to whether or not thebase station can transmit the paging signal to the first UE device usingthe unlicensed spectrum, a component 414 configured to determine if theconfigurable maximum number of transmission attempts has been reached,e.g., compare the current value of the variable transmission attempt tothe maximum number of transmission attempts, and to control operation asa function of the determination, a component 415 configured to incrementthe variable transmission attempt, a component 416 configured to operatethe base station to transmit a paging signal to said first UE deviceusing said unlicensed spectrum, when the determination is that the basestation can transmit the paging signal to the first UE device using theunlicensed spectrum, a component 420 configured to monitor to detect aresponse from said first UE device in response to the transmitted pagingsignal, and a component 424 configured to control the base station torefrain from transmitting a paging signal to said first UE device usingsaid unlicensed spectrum, when the determination is that the basestation can not transmit the paging signal to the first UE device usingthe unlicensed spectrum, e.g. because of the channel sensing conditionoperation determined that the unlicensed spectrum is currentlyunavailable. Component 416 includes a component 418 configured totransmit a paging message to said first UE device N number of timesand/or repetitively during a predetermined time interval T. Component420 includes a component 422 configured to receive a response from thefirst UE device in response to the transmitted paging signal.

Assembly of components 400 further includes a component 428 configuredto determine whether the paging operation was successful orunsuccessful. Component 428 includes a component 430 configured todetermine if a paging signal was transmitted to the first UE device aspart of said paging operation. Component 430 includes a component 432configured to determine that a paging signal was not transmitted to thefirst UE device, and a component 434 configured to determine that apaging signal was transmitted to the first UE device, e.g., based on anindication that component 416 operated the base station to transmit apaging signal. Component 428 further includes a component 436 configuredto control operation as a function of the determination as to whether ornot a paging signal was transmitted to the first UE device, a component438 configured to determine that the paging operation was not successfulin response to a determination that a paging signal was not transmittedto the first UE device. In some embodiments, component 438 storesinformation indicating that the paging operation was not successful dueto a failure to transmit a paging signal, e.g., due to unlicensedspectrum being currently unavailable. In some embodiments, the storedinformation is a failure cause code indicating the reason of thefailure. Component 428 further includes a component 440 configured todetermine if a response was received by the base station in response tothe paging signal transmitted to the first UE device, e.g., under thecontrol of component 416, a component 442 configured to controloperation as a function of the determination as to whether or not aresponse signal was received by the base station in response to thepaging signal transmitted to the first UE device, a component 444configured to determine that the paging operation was successful, whenthe determination is that response signal was received by the basestation in response to the paging signal transmitted to the first UEdevice, and a component 446 configured to determine that the pagingoperation was not successful in response to a determination that aresponse signal was not received by the base station in response to thepaging signal transmitted, e.g. under the control of component 416, tothe first UE device. In some embodiments, component 446 storesinformation indicating that the paging operation was not successful dueto a failure to receive a paging response signal, e.g., the pagingsignal directed to the first UE device was transmitted by the basestation, but the base station did not receive a response signal, e.g.,because the first UE was not in the coverage area of the base station orthe UE was powered off In some embodiments, the stored information is afailure cause code indicating the reason of the paging operation failureis that the base station did not receive a paging response signal inresponse to a transmitted paging signal.

Assembly of components 400 further includes a component 450 configuredto control operation as a function of the determination as to whetherthe paging operation was successful or unsuccessful, a component 452configured to communicate a paging response, e.g., a paging responsefailure message, to the network node in response to said first pagingrequest indicating that the paging operation was unsuccessful, inresponse to the base station determining that the paging operation wasunsuccessful, and a component 454 configured to perform one of thefollowing, in response to determining that the paging operation wasunsuccessful: i) proceeding with normal base station operation withoutsending a paging response message to the network node in response to thefirst paging request or ii) sending a paging success response message tothe network node in response to said first paging request.

Component 452 includes a component 456 configured to operate the basestation to transmit a paging response to the first network node thatincludes a failure cause code indicating the reason that the pagingoperation failed.

Component 456 includes a component 458 configured to operate the basestation, e.g., operate a transmitter in the base station, to transmit apaging response to the network node that includes a failure cause codeindicating the reason that the paging operation failed was due to afailure by the base station to transmit the paging signal to the firstUE device and a component 460 configured to operate the base station,e.g., operate a transmitter in the base station, to transmit a pagingresponse to the network node that includes a failure cause codeindicating the reason that the paging operation failed was due to afailure to receive a reply for the first UE device.

FIG. 5 is a drawing of an exemplary communications system 500 usinglicensed and unlicensed spectrum in accordance with an exemplaryembodiment. Communications system 500 includes an access and mobilityfunction (AMF) device 502, primary node (PN) base station (BS) 1 504,e.g., gNBP1, primary node (PN) base station (BS) 2 506, e.g., gNBP2,secondary node (SN) base station (BS) 1 508, e.g., gNBS1, secondary node(SN) base station (BS) 2 510, e.g., gNBS2, secondary node (SN) basestation (BS) 3 512, e.g., gNBS3, and secondary node (SN) base station(BS) 4 514, e.g., gNBS4, which are coupled together as shown in FIG. 5.Each base station (504, 506, 508, 510, 512, 514) has a correspondingwireless coverage area (505, 507, 509, 511, 513, 515). In this example,the PN base stations (504, 506) use licensed spectrum and a primarycarrier, while the SN base stations (508, 510, 512, 514) use unlicensedspectrum and one or more secondary carriers. In this example, the SNbase stations (508, 510, 512, 514) have been strategically deployed tofill in coverage gaps in the PN base stations (504, 506) coverage areas(505, 507), respectively. In some embodiments, the PN base stations(504, 506), may and sometimes do, use unlicensed spectrum.

AMF device 502 is coupled to PN BS 1 504 via communications link 550.AMF device 502 is coupled to PN BS 2 506 via communications link 551. PNBS 1 504 is coupled to SN BS 1 508 via communications link 516. PN BS 1504 is coupled to SN BS 2 510 via communications link 518. PN BS 2 506is coupled to SN BS 3 512 via communications link 522. PN BS 2 506 iscoupled to SN BS 4 514 via communications link 520.

Exemplary communications system 500 further includes a plurality of userequipment (UE) devices (UE 1 524, UE 2 526, UE 3 528, UE 4 530, UE 5532), which may move through the communications system. In FIG. 5, UE 1524 is shown to be within an area which can be reached by a pagingsignal from PN BS 1 504; UE 2 526 is shown to be within an area whichcan be reached by a paging signal from SN BS 1 508; UE 3 528 is shown tobe within an area which cannot be reached by a paging signal; UE 4 530is shown to be within an area which can be reached by a paging signalfrom PN BS 2 506; and UE 5 532 is shown to be within an area which canbe reached by a paging signal from SN BS 4 514.

FIG. 6-8 illustrate an exemplary paging attempt in accordance with anexemplary embodiment corresponding to the system 500 of FIG. 5. In FIG.6, AMF device 502 generates and sends a paging request message 602 to PNBS 1 504. The paging request message 602 includes informationidentifying that UE 2 is to paged, and further includes informationcommunicating that the paging is to be performed for both the mastercarrier group and secondary carrier group base stations. In thisexample, PN BS 504 uses the master carrier which is a primary carrierusing licensed spectrum, and the SN BSs 508, 510, use one or moresecondary carriers using unlicensed spectrum.

PN BS 1 504 receives the paging request message 602, recovers thecommunicated information, determines that it is to page for UE 2 andthat SN BSs 506 and 508 are also to page for UE 2, generates pagingrequest messages 604, 606 including information identifying that UE 2 isthe paging target, and sends paging request messages (604, 606) to SNBSs (508, 510), respectively, which receive the messages (604, 606) andrecover the communicated information.

In drawing 700 of FIG. 7, PN BS 1 504 generates and transmits pagingsignal 702, which is paging UE2, using the primary carrier in licensedspectrum. PN BS 1 504 monitors for a paging response from UE 2 inresponse to the transmitted paging signal, as indicated by block 703. Insome embodiments, the paging signal 702 may be transmitted apredetermined number of times or during a predetermined time interval,assuming no response is received.

In drawing 700 of FIG. 7, SN BS 1 508 attempts to transmit a pagingsignal using unlicensed spectrum. However, SN BS 1 508 is unable totransmit a paging signal to UE 2 because the unlicensed spectrum iscurrently unavailable, e.g., based on the results of a channel sensingoperation which is performed, as indicated by block 704.

In drawing 700 of FIG. 7, SN BS 2 510 generates and transmits pagingsignal 706, which is paging UE2, using a secondary carrier in unlicensedspectrum. PN BS 2 504 monitors for a paging response from UE 2 inresponse to the transmitted paging signal, as indicated by block 707. Insome embodiments, the paging signal 706 may be transmitted apredetermined number of times or during a predetermined time interval,assuming no response is received.

FIG. 8 includes drawing 800 which illustrates exemplary paging responsemessages (802, 804, 806) in accordance with an exemplary embodiment. SNBS 1 508 generates and sends paging response message 802 to PN BS 1 504,in response to paging request message 604. Paging response message 802includes information communicating that the paging attempt to page UE 2failed and the reason of the failure was that a paging message was notsent by SN BS 1 508, e.g., because the unlicensed spectrum wasunavailable. SN BS 2 510 generates and sends paging response message 804to PN BS 1 504, in response to paging request message 606. Pagingresponse message 804 includes information communicating that the pagingattempt to page UE 2 failed and the reason of the failure was that thetarget UE, which is UE 2, did not respond to the transmitted pagingsignal, i.e., the target UE was not present in the coverage area 511.

PN BS 1 504 receives the response messages (802, 804), recovers thecommunicated information, and generates a paging response message 806based on the information in response messages 802, 804 and based on itsown paging results for UE 2 in licensed spectrum, which also resulted infailure. Paging response message 806 includes information communicatingthat the paging attempt to page UE 2 failed and further includesinformation identifying the reason for failure in each of secondarycoverage areas, which use unlicensed spectrum. Thus paging responsemessage includes a failure code, corresponding to SN BS 1 508,indicating that a paging message was not sent in the area of SN BS 1 508(e.g., because unlicensed spectrum was not available), and a failurecode, corresponding to SN BS 2 510, indicating that the target UE, whichis UE 2, was not present in the area of SN BS 2 (e.g., SN BS 2 510transmitted a paging signal in unlicensed spectrum but received noresponse from UE 2).

MS BS 1 504 sends response message 806 to AMF device 502 in response tothe paging request message 602. The AMF 502 receives message 806,recovers the communicated information, and uses the information to makefuture paging request decisions, e.g., the AMF 502 implements anefficient paging escalation strategy as a function of one or morereceived failure codes.

In some embodiments, a paging message is sent to the Primary node (PN)als primary gNB or ng-eNB and Secondary Nodes (SN) als secondary gNB orng-eNB.

Some aspects and/or feature of an exemplary case 1: NR-U DC (newradio-unlicensed dual connectivity) operation will be discussed below.In some embodiment, if PN (gNB or ng-eNB) is allowed to instruct SN (gNBor ng-eNB) to page in addition to itself, then it does so. Therefore, PNand any selected SNs (by PN) will start paging the identified UE(s).This could, and sometimes does, include licensed and unlicensedcarriers. In some embodiments, each SN node will attempt to re-transmitthe page message N number of times and/or for T duration. Should noresponse be received from the UE and/or the paging message was not sentdue to LBT not clearing for unlicensed carriers, involved SNs will senda novel paging response message, e.g., Xn-A:PAGING_U RESPONSSE messageto PN over Xn. Once PN has received Xn-AP:PAGIN_U RESPONSE msg from someor all SNs, PN decides to send a paging responses message to AMF, e.g.,N2-AP:PAGING_U RESPONSE to AMF, indicating appropriate cause code (UEnot responding Or Message not sent due to non-availability of unlicensedchannels).

The criteria for how the PN selects SNs to instruct to page is up to theparticular implementation. It can, and sometimes does, depend on variousthings including: a) indicator from AMF as to whether paging via SN isallowed, and/or b) radio network planning data.

Some aspects and/or feature of an exemplary case 2: NR-U SA (newradio-unlicensed stand alone) operation will be discussed below. Case 2is similar to case 1, except there is only PN; there are no SNs.Therefore no X2 signaling is required.

FIG. 9 is a drawing 900 which illustrate an exemplary paging attempt,corresponding to the system 100 of FIG. 1, in which the paging attemptfails due to unavailable unlicensed spectrum in accordance with anexemplary embodiment. AMF device 102 generates and sends first pagingrequest message 902, which indicates that UE 1 110, is to be paged, tobase station 1 104, which uses unlicensed spectrum. Base station 1 104receives the paging request message 902 and attempts to page UE 1 110.As part of the paging attempt, BS 1 104 performs a channel sensingoperation which determines that the unlicensed spectrum is unavailablefor BS 104 to use at the present time, as indicated by box 904.Therefore BS 1 104 is unable to transmit a paging signal in theunlicensed spectrum to page UE 1 110. In some embodiments BS 1 104repeats the channel sensing operation to see if the unlicensed spectrumhas become available until a predetermined time interval expires, inwhich case the base station determines that the paging attempt isunsuccessful due to a failure by BS 1 104 to transmit a paging signal.Base station 1 104 generates and sends paging response message 906 toAMF device 102. The paging response message 906 indicates the pagingattempt for UE 1 was a failure and the paging response message 906includes a failure cause code indicating the failure is due to a failureby the base station to transmit a paging signal to UE 1. AMF device 102receives paging response message 102 and recovers the communicatedinformation. Thus the AMF 102 is aware the base station 104 was unableto transmit a paging signal, and may send another paging request at alater time.

FIG. 10 is a drawing 1000 which illustrate an exemplary paging attempt,corresponding to system 100 of FIG. 1, in which the paging attempt failsdue to no response from the UE device being paged in accordance with anexemplary embodiment. AMF device 102 generates and sends first pagingrequest message 1002, which indicates that UE 4 116, is to be paged, tobase station 1 104, which uses unlicensed spectrum. Base station 1 104receives the paging request message 1002 and attempts to page UE 4 116.As part of the paging attempt, BS 1 104 performs a channel sensingoperation which determines that the unlicensed spectrum is available forBS 104 to use at the present time, as indicated by box 1004. ThereforeBS 1 104 generates and transmits a paging signal 1006 in the unlicensedspectrum to page UE 4 116. Base station 1 104 monitors for a responsefrom UE 4 to the transmitted paging signal 1008. In some embodiments BS1 104 repetitively transmits the paging signal for a predeterminednumber of time or until a predetermined time interval expires, in whichcase the base station determines that the paging attempt is unsuccessfuldue to a failure to detect a response signal from UE 4 116. In theexample of FIG. 10, UE 4 116 is not currently in the coverage area 105of base station 1 104; therefore, UE 4 116 does not receive pagingsignal 1006 and does not send a response signal. Base station 1 104generates and sends paging response message 1010 to AMF 102, in responseto first paging request message 1002. Paging response message 1010indicates that the paging attempt to page UE 4 was a failure and thepaging response message 1010 includes a failure cause code indicatingthat the failure is a failure by the base station to receive a replyfrom the paging target UE, which is UE 4, to the transmitted pagingsignal 1006. AMF 102 receives paging response message 1108 and recoversthe communicated information. The AMF 102 is now aware that the pagingattempt failed due to UE 4 not being in the coverage area of BS 1 104,and the AMF can make an intelligent choice to send to a paging requestfor UE 4 to another area in which UE may be located since the region105, corresponding to BS 1 104, has been eliminated.

FIG. 11 is a drawing 1100 which illustrate an exemplary paging attempt,corresponding to the system 100 of FIG. 1, in which the paging attemptis a success in accordance with an exemplary embodiment. AMF device 102generates and sends first paging request message 1102, which indicatesthat UE 1 110, is to be paged, to base station 1 104, which usesunlicensed spectrum. Base station 1 104 receives the paging requestmessage 1102 and attempts to page UE 1 110. As part of the pagingattempt, BS 1 104 performs a channel sensing operation which determinesthat the unlicensed spectrum is available for BS 104 to use at thepresent time, as indicated by box 1104. Therefore BS 1 104 generates andtransmits a paging signal 1106 in the unlicensed spectrum to page UE 1110. Base station 1 104 monitors for a response from UE 1 110 to thetransmitted paging signal 1106. In the example of FIG. 11, UE 1 110 iscurrently in the coverage area 105 of base station 1 104; therefore, UE1 110 does receive paging signal, and UE 1 110 generates and transmitspaging response signal 1108 to base station 1 104. Base station 1 104receives the paging response signal 1108. Base station 1 104 generatesand sends paging response message 1110 to AMF 102, in response to firstpaging request message 1102. Paging response message 1110 indicates thatthe paging attempt to page UE 1 was a success. AMF 102 receives pagingresponse message 1110 and recovers the communicated information.

FIG. 12 is a drawing of an exemplary user equipment (UE) device 1200implemented in accordance with an exemplary embodiment. UE device 1200is, e.g. one of the UE devices (110, 112, 114, 116, 118, 120, 122) ofsystem 100 of FIG. 1 or one of the UE devices (524, 526, 528, 530, 532)of system 500 of FIG. 5. UE device 1200 includes a processor 1202, awireless interface 1204, a network interface 1210, an I/O interface1216, an assembly of hardware components 1218, e.g., an assembly ofcircuits, and memory 1220 coupled together via a bus 1222 over which thevarious elements may interchange data and information. Wirelessinterface 1204 includes a wireless receiver 1238 coupled to receiveantenna 1239, via which the UE may receive wireless signals, e.g.,wireless downlink signals from a base station, e.g., a gNB. An exemplarysignal received by receiver 1238 is a paging signal from a base stationwhich was communicated over unlicensed spectrum. Wireless interface 1204includes a wireless transmitter 1240 coupled to transmit antenna 1241,via which the UE may transmit wireless signals, e.g., wireless uplinksignals to a base station, e.g., a gNB. An exemplary signal transmittedby transmitter 1240 is a paging response signal to a base station.Network interface 1210, e.g., a wired or optical interface 1210 includesa receiver 1278 and a transmitter 1280.

UE device 1200 further includes a microphone 1224, a speaker 1226,switches 1228, a mouse 1234, a keypad 1232, a display 1230 and a camera1236 coupled to I/O interface 1216, via which the various input/outputdevices (1224, 1226, 1228, 1230, 1232, 1234, 1236) may communicate withthe other elements (1202, 1204, 1210, 1218, 1220) of the UE device.Memory 1220 includes a control routine 1252, an assembly of components1254, e.g., an assembly of software components, and data/information1256.

FIG. 13 is a drawing of an exemplary network node 1300, e.g., an AMF,implemented in accordance with an exemplary embodiment. Exemplarynetwork node 1300 is, e.g., AMF device 102 of system 100 of FIG. 1 orAMF device 502 of system 500 of FIG. 5. Network node 1300 includes aprocessor 1302, e.g., a CPU, a network interface 1304, an input device1306, e.g., a keyboard, an output device 1308, e.g., a display, anassembly of hardware components 1310, e.g., an assembly of circuits, andmemory 1312 coupled together via a bus 1314 over which the variouselements may interchange data and information. Network interface 1304,e.g., a wired or optical interface, includes a receiver 1316 and atransmitter 1318, via which network node 00 may communicate with otherdevices, e.g., a base station, another core network element, etc., via abackhaul network. Memory 1312 includes a control routine 1320, anassembly of components 1322, e.g., an assembly of software components,and data/information 1324.

FIG. 14, comprising the combination of FIG. 14A and FIG. 14B, is adrawing of an exemplary assembly of components 1400, comprising Part A1401 and Part B 1403, in accordance with an exemplary embodiment.Exemplary assembly of components 1400 may be, and sometimes is, includedin an exemplary network node, e.g., network node 1300, e.g., an AMF, ofFIG. 13, or network node 102, e.g., an AMF, of system 100 of FIG. 1 orAMF 502 of system 500 of FIG. 5, and implement steps of an exemplarymethod, e.g., steps of the method of the flowchart 200 of FIG. 2.

The components in the assembly of components 1400 can be, and in someembodiments are, implemented fully in hardware within the processor1302, e.g., as individual circuits. The components in the assembly ofcomponents 1400 can, and in some embodiments are, implemented fully inhardware within the assembly of components 1310, e.g., as individualcircuits corresponding to the different components. In other embodimentssome of the components are implemented, e.g., as circuits, within theprocessor 1302 with other components being implemented, e.g., ascircuits within assembly of components 1310, external to and coupled tothe processor 1302. As should be appreciated the level of integration ofcomponents on the processor and/or with some components being externalto the processor may be one of design choice. Alternatively, rather thanbeing implemented as circuits, all or some of the components may beimplemented in software and stored in the memory 1312 of the networknode 1300, e.g., an AMF, with the components controlling operation ofthe network node to implement the functions corresponding to thecomponents when the components are executed by a processor, e.g.,processor 1302. In some such embodiments, the assembly of components1400 is included in the memory 1312 as assembly of components 1322. Instill other embodiments, various components in assembly of components1400 are implemented as a combination of hardware and software, e.g.,with another circuit external to the processor providing input to theprocessor 1302 which then under software control operates to perform aportion of a component's function. While processor 1302 is shown in theFIG. 13 embodiment as a single processor, e.g., computer, it should beappreciated that the processor 1302 may be implemented as one or moreprocessors, e.g., computers.

When implemented in software the components include code, which whenexecuted by the processor 1302, configure the processor 1302 toimplement the function corresponding to the component. In embodimentswhere the assembly of components 1400 is stored in the memory 1312, thememory 1312 is a computer program product comprising a computer readablemedium comprising code, e.g., individual code for each component, forcausing at least one computer, e.g., processor 1302, to implement thefunctions to which the components correspond.

Completely hardware based or completely software based components may beused. However, it should be appreciated that any combination of softwareand hardware, e.g., circuit implemented components may be used toimplement the functions. As should be appreciated, the componentsillustrated in FIG. 14 control and/or configure the network node 1300,or elements therein such as the processor 1302, to perform the functionsof corresponding steps illustrated and/or described in the method of oneor more of the flowcharts, signaling diagrams and/or described withrespect to any of the Figures. Thus the assembly of components 1400includes various components that perform functions of corresponding oneor more described and/or illustrated steps of an exemplary method, e.g.,steps of the method of flowchart 200 of FIG. 2 and/or described or shownwith respect to any of the other figures.

Assembly of components 1400 includes a component 1404 configured togenerate a first paging request, said first paging request being arequest to page a first UE device, a component 1406 configured to sendthe generated first paging request to a first base station usingunlicensed spectrum, and a component 1464 configured to monitor for apaging response message, e.g., a paging failure response message or apaging success response message, from the first base station, which wassent to the network node in response to the first paging requestmessage. Component 1464 includes a component 1466 configured to operatethe network node to receive a paging response message.

Assembly of component 1400 further includes a component 1468 configuredto determine if a received paging response message is a paging failureresponse message or a paging success response message, a component 1469configured to recover a failure cause code communicated in the receivedpaging response failure message, e.g., in response to a determinationthat the received paging response message is a paging failure responsemessage, and a component 1472 configured to determine that the paging ofthe first UE has been successful in response to said received pagingresponse message being a paging success response message.

Assembly of component 1400 further includes a component 1470 configuredto implement a paging escalation strategy as a function of the failurecause code in the received paging failure response message. Component1470 includes a component 1474 configured to determine if thecommunicated failure cause code indicates that the paging signal wastransmitted but no response was received and to control operation as afunction of the determination, a component 1476 configured to determineto change the paging area of the first UE device in response to adetermination that the paging signal was transmitted, e.g., to the firstUE device, but no response was received, e.g., from the first UE device,and a component 1478 configured to determine if: i) the communicatedfailure cause code indicates that the first base station was unable totransmit an intended paging signal because of non-availability of anunlicensed carrier and ii) the first paging request message was aninitial attempt of paging the first UE via the unlicensed spectrum ofthe first base station. Assembly of components 1400 further includes acomponent 1479 configured to determine to change the paging area of thefirst UE device in response to a determination that: i) the communicatedfailure cause code indicates that the first base station was unable totransmit an intended paging signal because of non-availability of anunlicensed carrier and ii) the first paging request message was not aninitial attempt of paging the first UE device via unlicensed spectrum ofthe first base station. Assembly of components 1400 further includes acomponent 1480 configured to send a paging request to a second basestation requesting the second base station to page the first UE device,in response to a determination to change the paging area of the first UEdevice, and a component 1484 configured to re-send the first pagingrequest to the first base station, e.g., in response to a determinationthat the communicated failure cause code indicates that the first basestation was unable to transmit an intended paging signal because ofnon-availability of an unlicensed spectrum and ii) the first pagingrequest message was an initial attempt of paging the first UE device viaunlicensed spectrum of the first base station.

Various aspects and/or features are described below. Various aspectsand/or features of paging in some embodiments of new radio (NR) will nowbe described. In some embodiments, Core network (CN)-based pagingoperations in NR are similar to Long Term Evolution (LTE). For RRC_IDLEUEs, Access and Mobility Management Function (AMF) informs NG-RAN node(either gNB or ng-eNB) to initiate paging for the UE identified via5G-S-TMSI in certain cells/Tracking area (TA) via N2-AP: PAGIN message.NG-RAN node pages target UEs via RRC:PAGING message. If target UEs donot respond to the page in a certain time duration, then AMF canre-initiate paging. At this juncture, paging escalation strategies maybe applied, e.g., previous page msg was restricted to few cells in oneTA, but re-paging may involve increasing the paging area to e.g., allcells in that tracking area or all cells in multiple TAs, etc.

NR introduces RAN-based paging operations based on I-RNTI to accommodatereaching UEs in the new RRC INACTIVE state. In case of DC operations inNR (EN-DC, NGEN-DC or MR-DC), paging operation is currently performedonly on primary carrier (MCG) which uses licensed spectrum.

It is important to note that unlike most other RAN-CN messages, theN2-AP:PAGING message has no N2-AP response event. In accordance with afeature of some embodiments of the present invention, a response messageis added, e.g., a base station such as gNB, transmits a response messageto network node such as an AMF node, in response to a paging requestmessage.

Various aspects and/or features of some embodiments of new radiounlicensed spectrum (NR-U) will now be described. NR in UnlicensedSpectrum (NR-U) SID which is being studied in 3GPP Rel-15/16 has thefollowing 3 flavours: Carrier Aggregated (CA), Dual Connectivity (DC),and Standalone (SA). Carrier Aggregated (CA) is similar to LTE-LAA andapplies to both LTE- and NR-primary carrier licensed spectrum. DualConnectivity (DC) applies to both LTE- and NR-primary carrier inlicensed spectrum. Standalone (SA) NR-U applies only to NR and nolicensed carrier exists; present day may use WiFi.

Among other operations, the paging operation would need to be definedfor NR-U SA. Note that paging mechanisms defied for NR will apply toNR-U CA and DC case with some modifications required. IPR on “porting”NR paging operations to NR-U SA are assumed to exist.

Various problems related to paging will now be described. A first issuewill now be described. For NR-U, sending any messages over unlicensedmedium comes with the uncertainty of not having access to the physicalmedium for transmission at the desired time of transmission. If NR-U SApaging operations use NR paging operations as the baseline, it would besafe to assume that if target UE(s) do not respond to the paging, thenAMF will re-initiate paging but it will escalate to a wider area. But,AMF would not have the knowledge of whether target UE(s) are notresponding to CN pages because: i) target UE(s) are not present in thearea being paged or ii) paging message was not sent (access to mediumwas not gained).

A second issue will now be described. For NR-U DC operations, primarycarrier (MSG) coverage (using FR1 or FR2) can be expected to coverunlicensed secondary carrier(s) (SGC) coverage area. However, that maynot always be true for either hot-spot type deployment where unlicensedcarriers are deployed to fill FR1 coverage gaps and/or for coverageextension. For non-overlapping coverage areas, if UE is not in thecoverage area of the primary cell, but is in secondary carrier (onunlicensed spectrum), then paging will have to be unnecessarilyescalated to multiple primary cells, e.g., more than 1 tracking area(TA) to get to the UE.

A solution to the first issue will now be described. In accordance witha feature of some embodiments of the present invention, a new Class 1N2-AP:PAGING_U message with a corresponding N2-AP:PAGING_U RESPONSEmessage including a failure cause code is implemented. Thus, inaccordance with a feature of some embodiments of the present invention,a base station, e.g., a gNB, generates and sends a paging response tothe network node, e.g., an AMF node, indicating the reason for thepaging failure. Thus the AMF is provided, in accordance with the presentinvention, will knowledge of why the target UEs which are being pagedare not responding to the core network (CN) pages.

A solution to the second issue will now be described. In someembodiments implemented in accordance with the present invention, pagingoperations on (unlicensed) Secondary unlicensed carrier(s) areimplemented. Some such embodiments are implemented to support thecapability of exchanges between UE, NG-RAN, e.g., a gNB, and SGC, e.g.,a AMF, to support paging over (unlicensed) Secondary carrier(s). In someembodiments, a new IE is implemented and used to enable/disable(unlicensed) Secondary carrier(s) paging duringRRC_IDLE/RRC_INTERACTIVE→RRC_CONNECTED transitions. In some embodiments,a new IE is implemented and used in N2-AP:PAGING msg to control whethera given PAGING message goes on MCG or SCGs or both. In some embodiments,UE enhancements are implemented and used to automatically disablelistening for pages on (unlicensed) Secondary carrier(s) if no pages arereceived in a certain time window.

First Numbered List of Exemplary Method Embodiments

Method Embodiment 1 A method of operating a communications systemincluding at least one base station (e.g., gNB or ng-eNB) that usesunlicensed spectrum, the method comprising: receiving (208), at a firstbase station a first paging request from a network node, e.g., an (AMF),used to control paging of user equipment (UE) devices, said first pagingrequest being a request to page a first UE device; operating (210) thefirst base station to perform a paging operation to page the first UEdevice using unlicensed spectrum; operating (228) the first base stationto determine whether said paging operation was successful orunsuccessful; when it is determined that said paging operation wasunsuccessful, operating (252) the first base station to communicate apaging response to the network node in response to said first pagingrequest indicating that the paging operation was unsuccessful; and whenit is determined that said paging operation was successful, operating(254) the first base station to perform one of i) proceeding with normalbase station operation without sending a paging response message to thenetwork node in response to said first paging request or ii) sending apaging success response message to the first network node in response tosaid paging request.

Method Embodiment 2 The method of Method Embodiment 1, wherein operating(210) the first base station to perform a paging operation includes:operating (212) the first base station to perform a channel sensingcondition to determine if the first base station can transmit a page tothe first UE using said unlicensed spectrum; operating (216) the firstbase station to transmit a paging signal to said UE device using saidunlicensed spectrum when said channel sensing condition determines thatthe first base station can transmit the page to the first UE deviceusing said unlicensed spectrum; and operating (224) the first basestation to refrain from transmitting the paging signal to said UE whensaid channel sensing condition determines that the first base station isnot authorized (e.g., because the channel is busy) to transmit the pageto the first UE using said unlicensed spectrum.

Method Embodiment 3 The method of Method Embodiment 1, wherein operating(228) the first base station to determine whether said paging operationwas successful or unsuccessful includes: operating (230) the first basestation to determining if a paging signal was transmitted to said firstUE device as part of said paging operation; and operating (246) thefirst base station to determine that the paging operation was notsuccessful when it is determined that paging signal was not transmittedto the first UE as part of said paging operation.

Method Embodiment 4 The method of Method Embodiment 3, wherein themethod includes operating (234) the first base station to determine thatpaging signal was not transmitted to the first UE device as part of saidpaging operation; and wherein operating (252) the first base station tocommunicate a paging response to the network node in response to saidfirst paging request indicating that the paging operation wasunsuccessful includes operating (258) the first base station to transmita paging response to the first network node that includes a failurecause code indicating that the reason the paging operation failed wasdue to a failure by the first base station to transmit the paging signalto the first UE device.

Method Embodiment 5 The method of Method Embodiment 1, wherein operating(228) the first base station to determine whether said paging operationwas successful or unsuccessful includes: operating (240) the first basestation to determine whether a response was received by the base stationfrom the first UE device in response to a paging signal transmitted tothe first UE device.

Method Embodiment 6 The method of Method Embodiment 4, wherein operating(228) the first base station to determine whether said paging operationwas successful or unsuccessful includes: operating (246) the first basestation to determine that the paging operation was successful based on adetermination that a response was received by the base station from thefirst UE device in response to the paging signal transmitted to thefirst UE device.

Method Embodiment 7 The method of Method Embodiment 6, wherein operating(228) the first base station to determine whether said paging operationwas successful or unsuccessful includes: operating (246) the first basestation to determine that the paging operation was not successful basedon a determination that a response was not received by the base stationfrom the first UE device in response to the paging signal transmitted tothe first UE device.

Method Embodiment 8 The method of Method Embodiment 7, wherein operating(252) the first base station to communicate the paging response to thenetwork node in response to said first paging request indicating thatthe paging operation was unsuccessful includes operating (260) the firstbase station to transmit a paging response to the first network nodethat includes a failure cause code indicating that the reason the pagingoperation failed was due to a failure to receive a reply from the firstUE device (e.g., in response to the transmitted paging signal).

Method Embodiment 9 The method of Method Embodiment 1, furthercomprising: operating (270) the network node to implement a pagingescalation strategy as a function of a failure cause code in a receivedpaging response message.

Method Embodiment 10 The method of Method Embodiment 9, wherein saidpaging operation was unsuccessful, wherein said paging responsecommunicated a failure cause code indicating that the reason that thepaging operation failed was due to a failure to receive a reply from thefirst UE device, and wherein operating (270) the network node toimplement a paging escalation strategy as a function of a failure causecode in a received paging response message includes: operating (280) thenetwork node to send a paging request to a second base stationrequesting the second base station to page the first UE device, inresponse to said communicated failure cause code indicating that thereason that the paging operation failed was due to a failure to receivea reply from the first UE device.

Method Embodiment 11 The method of Method Embodiment 9, wherein saidpaging operation was unsuccessful, wherein said paging responsecommunicated a failure cause code indicating that the reason that thepaging operation failed was due to a failure by the first base stationto transmit the paging signal to the first UE device, and wherein saidfirst paging request was an initial attempt; and wherein operating (270)the network node to implement a paging escalation strategy as a functionof a failure cause code in a received paging response message includesoperating the network node to re-send (284) the first paging request tothe first base station, in response to said communicated failure causecode indicating that the reason that the paging operation failed was dueto a failure by the first base station to transmit the paging signal tothe first UE device (e.g., because of unavailability of unlicensedspectrum (LBT not clearing)) and said first paging request being aninitial attempt.

Numbered List of Exemplary System Embodiments

System Embodiment 1 A communications system (100) comprising: a firstbase station (e.g., gNB or ng-eNB) (104) that uses unlicensed spectrum,said first base station (104) including: a first processor (302)configured to: control the first base station to receive (208), at afirst base station a first paging request from a network node (102),e.g., an (AMIF), used to control paging of user equipment (UE) devices(110, 112, 114, 116, 118, 120, . . . , 122), said first paging requestbeing a request to page a first UE device (110); control the first basestation to perform (210) a paging operation to page the first UE deviceusing unlicensed spectrum; determine (228) whether said paging operationwas successful or unsuccessful; control the first base station tocommunicate (252) a paging response to the network node in response tosaid first paging request indicating that the paging operation wasunsuccessful, when it is determined that said paging operation wasunsuccessful, and control the first base station to perform (254) one ofi) proceeding with normal base station operation without sending apaging response message to the network node in response to said firstpaging request or ii) sending a paging success response message to thefirst network node in response to said paging request, when it isdetermined that said paging operation was successful.

System Embodiment 2 The communications system of System Embodiment 1,wherein said first processor is configured to: operate (212) the firstbase station to perform a channel sensing condition to determine if thefirst base station can transmit a page to the first UE using saidunlicensed spectrum; operate (216) the first base station to transmit apaging signal to said UE device using said unlicensed spectrum when saidchannel sensing condition determines that the first base station cantransmit the page to the first UE device using said unlicensed spectrum;and operate (224) the first base station to refrain from transmittingthe paging signal to said UE when said channel sensing conditiondetermines that the first base station is not authorized (e.g., becausethe channel is busy) to transmit the page to the first UE using saidunlicensed spectrum, as part of being configured to control (210) thefirst base station to perform a paging operation.

System Embodiment 3 The communications system of System Embodiment 1,wherein said first processor is configured to: operate (230) the firstbase station to determine if a paging signal was transmitted to saidfirst UE device as part of said paging operation; and operate (246) thefirst base station to determine that the paging operation was notsuccessful when it is determined that paging signal was not transmittedto the first UE as part of said paging operation, as part of beingconfigured to determine whether said paging operation was successful orunsuccessful.

System Embodiment 4 The communications system of System Embodiment 3,wherein said first processor is configured to: operate (234) the firstbase station to determine that paging signal was not transmitted to thefirst UE device as part of said paging operation; and operate (258) thefirst base station to transmit a paging response to the first networknode that includes a failure cause code indicating that the reason thepaging operation failed was due to a failure by the first base stationto transmit the paging signal to the first UE device, as part of beingconfigured to operate (252) the first base station to communicate apaging response to the network node in response to said first pagingrequest indicating that the paging operation was unsuccessful.

System Embodiment 5 The communications system of System Embodiment 1,wherein said first processor is configured to: operate (240) the firstbase station to determine whether a response was received by the basestation from the first UE device in response to a paging signaltransmitted to the first UE device, as part of being configured tooperate (228) the first base station to determine whether said pagingoperation was successful or unsuccessful includes:

System Embodiment 6 The communications system of System Embodiment 4,wherein said first processor is configured to: operate (246) the firstbase station to determine that the paging operation was successful basedon a determination that a response was received by the base station fromthe first UE device in response to the paging signal transmitted to thefirst UE device, as part of being configured to determine (228) whethersaid paging operation was successful or unsuccessful.

System Embodiment 7 The communications system of System Embodiment 6,wherein said first processor is configured to operate (246) the firstbase station to determine that the paging operation was not successfulbased on a determination that a response was not received by the basestation from the first UE device in response to the paging signaltransmitted to the first UE device, as part of being configured todetermine (228) whether said paging operation was successful orunsuccessful.

System Embodiment 8 The communications system of System Embodiment 7,wherein said first processor is configured to: operate (260) the firstbase station to transmit a paging response to the first network nodethat includes a failure cause code indicating that the reason the pagingoperation failed was due to a failure to receive a reply from the firstUE device (e.g., in response to the transmitted paging signal), as partof being configured to control (252) the first base station tocommunicate the paging response to the network node in response to saidfirst paging request indicating that the paging operation wasunsuccessful.

System Embodiment 9 The communications system (100) of System Embodiment1, further comprising: said network node (102) including a secondprocessor (1302); and wherein said second processor is configured to:operate (270) the network node to implement a paging escalation strategyas a function of a failure cause code in a received paging responsemessage.

System Embodiment 10 The communications system of System Embodiment 9,wherein said paging operation was unsuccessful, wherein said pagingresponse communicated a failure cause code indicating that the reasonthat the paging operation failed was due to a failure to receive a replyfrom the first UE device, and wherein said second processor isconfigured to operate (280) the network node to send a paging request toa second base station requesting the second base station to page thefirst UE device, in response to said communicated failure cause codeindicating that the reason that the paging operation failed was due to afailure to receive a reply from the first UE device, as part of beingconfigured to operate (270) the network node to implement a pagingescalation strategy as a function of a failure cause code in a receivedpaging response message includes:

System Embodiment 11 The communications system of System Embodiment 9,wherein said paging operation was unsuccessful, wherein said pagingresponse communicated a failure cause code indicating that the reasonthat the paging operation failed was due to a failure by the first basestation to transmit the paging signal to the first UE device, andwherein said first paging request was an initial attempt; and whereinsaid second processor is configured to operate the network node tore-send (284) the first paging request to the first base station, inresponse to said communicated failure cause code indicating that thereason that the paging operation failed was due to a failure by thefirst base station to transmit the paging signal to the first UE device(e.g., because of unavailability of unlicensed spectrum (LBT notclearing)) and said first paging request being an initial attempt, aspart of being configured to operate (270) the network node to implementa paging escalation strategy as a function of a failure cause code in areceived paging response message.

Number List of Exemplary Computer Readable Medium Embodiments

Computer Readable Medium Embodiment 1 A non-transitory computer readablemedium (310) including computer executable instructions which whenexecuted by a processor (302) control a first base station (104 or 300)that uses unlicensed spectrum to perform the steps of: receiving, atsaid first base station a first paging request from a network node, usedto control paging of user equipment (UE) devices, said first pagingrequest being a request to page a first UE device; operating the firstbase station to perform a paging operation to page the first UE deviceusing unlicensed spectrum; operating the first base station to determinewhether said paging operation was successful or unsuccessful; when it isdetermined that said paging operation was unsuccessful, operating thefirst base station to communicate a paging response to the network nodein response to said first paging request indicating that the pagingoperation was unsuccessful; and when it is determined that said pagingoperation was successful, operating the first base station to performone of i) proceeding with normal base station operation without sendinga paging response message to the network node in response to said firstpaging request or ii) sending a paging success response message to thefirst network node in response to said paging request.

FIG. 15, comprising the combination of FIG. 15A, FIG. 15B, FIG. 15C andFIG. 15D, is a flowchart 1500 of an exemplary method of operating amacro cell base station in accordance with an exemplary embodiment. Themacro cell base station is, e.g., one of the macro cell base station(macro cell base station 1 1604, macro cell base station 2 1606) ofcommunications system 1600 of FIGS. 16-24.

Operation starts in step 1502 in which the macro cell base station ispowered on and initialized. Operation proceeds from step 1502 to step1504 and, via connecting node C 1551, to step 1554. In step 1504, themacro cell base station receives from a network node, e.g., from anaccess and mobility function (AMF), e.g., AMF device 1602 of system1600, a paging request to page a first UE. The first UE is, e.g. one ofthe UEs (UE 1 1634, UE 2 1636, UE 3 1638, UE 4 1640, UE 5 1642, UE 61644) of system 1600 of FIG. 16. Operation proceeds from step 1504 tostep 1506.

In step 1506 the macro cell base station determines a set of basestations which are to attempt to page the first UE, said determined setof base stations including at least one base station, said at least onebase station including the macro cell base station or a small cell basestation. In some embodiments, e.g., the embodiment of FIG. 16, the macrocell base station uses licensed spectrum and the small cell base stationuses unlicensed spectrum. In other embodiments, the macro cell basestation uses unlicensed spectrum and the small cell base stations useunlicensed spectrum, e.g., the macro cell base station uses unlicensedspectrum corresponding to a first frequency band and the small cell basestations use unlicensed spectrum corresponding to a second frequencyband, said second frequency band being different than said firstfrequency band. In some other embodiments, the macro cell base stationuses licensed spectrum corresponding to a first frequency band; somesmall cell base stations use licensed spectrum corresponding to a secondfrequency band, said second frequency band being different from saidfirst frequency band; and some small cell base stations use unlicensedspectrum.

Step 1506 includes step 1508, in which the macro cell base stationdetermines a group of small cell base stations to which the pagingrequest to page the first UE is to be communicated. Step 1508 includesone or more or all of: steps 1510, 1512, 1514, 1516, 1518, 1520, 1522,1524, 1526 or 1530. In step 1510 the macro cell base station determinesthe group of small cell base stations based on historical cellinformation submitted by the first UE to the macro cell base station,e.g., during RRC connection establishment or during RRC connectionrelease. In step 1512 the macro cell base station determines the groupof small cell base stations based on the first UE's mobility pattern,e.g., based on hysteresis information maintained by the macro cell basestation based on the first UE's mobility pattern. In step 1514 the macrocell base station determines the group of small cell base stations basedon measurement reports for the first UE, e.g., historical signalmeasurement reports communicated by the first UE. In step 1516 the macrocell base station determines the group of small cell base stations basedon channel quality information feedback for potential carrieraggregation (CA) target small cell base stations, e.g., communicated bythe first UE in measurement reports. In step 1518 the macro cell basestation determines the group of small cell base stations based onphysical downlink control channel (PDDCH) channel load on the macro celldue to paging operations. In step 1520 the macro cell base stationdetermines the group of small cell base stations based on the last knownor average strength, e.g., reference signal received quality (RSRQ) ofthe macro cell as reported by the first UE. In step 1522 the macro cellbase station determines the group of small cell base stations based onthe number of UEs requiring paging, e.g., at that instant of time. Instep 1524 the macro cell base station determines the group of small cellbase stations based on the number of small cells under (i.e. withvarying degrees of overlap) the macro cell's coverage area. In step 1526the macro cell base station determines the group of small cell basestations based on received radio network planning data feeddata/information, e.g. via Operations, Administration and Maintenance(OAM), updated via Automatic Neighbor Relations (ANR) and/or viaSelf-Organizing Networks (SON). In some embodiments, step 1526 includesstep 1528 in which the macro cell base station determines the group ofsmall cell base stations based on a received provision list of smallcells under its hierarchy. In step 1530 the macro cell base stationdetermines the group of small cell base stations based on received UEreports including first UE reports. Operation proceeds from step 1506 tostep 1532, if the determined group of small cell base stations includesat least one small cell base station; otherwise step 1532 is bypassed.

In step 1532 the macro cell base station sends the paging request topage the first UE to each of the small cell base stations in thedetermined group of small cell base stations. Step 1532 includes step1534 and may, and sometimes does, include additions steps, e.g. step1536, e.g., depending upon the number of small cell base stations in thedetermined group of small cell base stations. In step 1534 the macrocell base station sends a paging request to page the first UE to a firstsmall cell base station in said determined group of small cell basestations. In step 1536 the macro cell base station sends a pagingrequest to page the first UE to an Nth small cell base station in saiddetermined group of small cell base stations. Operation proceeds fromstep 1532, via connecting node A 1538 to 1540, if the macro cell basestation is one of the base stations in the determined set of basestations which are to attempt to page the first UE; otherwise, step 1540is bypassed.

In step 1540 the macro cell base station attempts to page the first UE,e.g. during a time interval in which the determined group of small cellbase stations attempts to page the first UE. Operation proceeds fromstep 1540 to step 1541, if the determined group of small cell basestation includes at least one small cell base station; otherwise, step1541 is bypassed.

In step 1541 the macro cell base station monitors for paging responsemessages from small cell base stations in said determined group of smallcell base stations. Step 1541 is performed on an ongoing basis, e.g.,for a predetermined time interval. Step 1541 may, and sometimes doesinclude one or more iterations of step 1542. In step 1542 the macro cellbase station receives a paging response message from a small cell basestation in said determined group of small cell base stations, saidreceived paging response message indicating one of: i) an attempt at thesmall cell base station to page the first UE device was successful orii) an attempt at the small cell base station to page the first UEdevice was unsuccessful. Step 1552 may, and sometimes does includes step1543.

In step 1543 the macro cell base station receives a response from asmall cell base station indicating that the paging attempt wasunsuccessful and further indicating the reason for the paging attemptfailure, e.g., i) the small cell base station was unable to transmit apaging signal to page the first UE because listen-before-talk (LBT)indicated the unavailability of unlicensed spectrum or ii) the first UEdid not respond to the transmitted paging signals. Operation proceedsfrom step 1541 to step 1544.

In step 1544 the macro cell base station determines whether the pagingattempt to page the first UE was successful or unsuccessful. Operationproceeds from step 1544 to step 15441.

In step 15441 the macro cell base station sends to the network node,e.g., to an AMF, a paging response message indicating one of success orfailure to page the first UE. Step 15441 includes steps 1545, 1546,1547, 1548, and 1549.

In step 1545 if the determination is that the paging attempt to page thefirst UE was successful, then operation proceeds from step 1545 to step1546; however, if the determination is that the paging attempt to pagethe first UE was unsuccessful then operation proceeds from step 1545 tostep 1547.

In step 1546, the macro cell base station sends, e.g., to the AMF, apaging response message indicating that the paging attempt to page thefirst UE was successful. In some embodiments, step 1546 is bypassed.

Returning to step 1547, in step 1547 the macro cell base stationdetermines if at least one of the base stations in the set of basestations determined to attempt to page the first UE intended to useunlicensed spectrum for the paging attempt. If the determination is thatnone of the base stations in the set of base stations determined toattempt to page the first UE intended to use unlicensed spectrum for thepaging attempt, then operation proceeds from step 1547 to step 1548 inwhich the macro cell base station sends, e.g. to the AMF, a pagingresponse message indicating that the attempt to page the first UEfailed. In some embodiments, the paging response message of step 1548indicates that the paging attempt failed because the first UE did notrespond to transmitted paging signals.

If the determination is that at least one of the base stations in theset of base stations determined to attempt to page the first UE intendedto use unlicensed spectrum for the paging attempt, then operationproceeds from step 1547 to step 1549 in which the macro cell basestation sends, e.g. to the AMF, a paging response message indicatingthat the attempt to page the first UE failed, said paging responsemessage indicating the reason or reason(s) that the paging attemptfailed, e.g., unavailability of unlicensed spectrum and/or the first UEdid not respond to transmitted paging signals. Operation proceeds fromstep 1546, step 1548 or step 1549, via connecting node B 1550, to step1504, in which the macro cell base station receives another pagingrequest to page the first UE. Operation proceeds from step 1504 to step1506. During different iterations of steps 1506 the macro cell basestation may, and sometime does, determine a different set of basestations and a different group of small cell base stations which are toattempt to page the first UE, e.g. depending upon current conditions.

Returning to step 1554, in step 1504, the macro cell base stationreceives from a network node, e.g., from the access and mobilityfunction (AMF), e.g., AMF device 1602 of system 1600, a paging requestto page a second UE. The second UE is, e.g. one of the UEs (UE 1 1634,UE 2 1636, UE 3 1638, UE 4 1640, UE 5 1642, UE 6 1644) of system 1600,and is a different UE than the first UE. Operation proceeds from step1554 to step 1556.

In step 1556 the macro cell base station determines a second set of basestations which are to attempt to page the second UE, said determinedsecond set of base stations including at least one base station, said atleast one base station including the macro cell base station or a smallcell base station.

Step 1556 includes step 1558, in which the macro cell base stationdetermines a second group of small cell base stations to which thepaging request to page the second UE is to be communicated. Step 1558includes one or more or all of: steps 1560, 1562, 1564, 1566, 1568,1570, 1572, 1574, 1576 or 1580. In step 1560 the macro cell base stationdetermines the second group of small cell base stations based onhistorical cell information submitted by the second UE to the macro cellbase station, e.g., during RRC connection establishment or during RRCconnection release. In step 1562 the macro cell base station determinesthe second group of small cell base stations based on the second UE'smobility pattern, e.g., based on hysteresis information maintained bythe macro cell base station based on the second UE's mobility pattern.In step 1564 the macro cell base station determines the second group ofsmall cell base stations based on measurement reports for the second UE.In step 1566 the macro cell base station determines the second group ofsmall cell base stations based on channel quality information feedbackfor potential carrier aggregation (CA) target small cell base stations.In step 1568 the macro cell base station determines the second group ofsmall cell base stations based on physical downlink control channel(PDDCH) channel load on the macro cell due to paging operations. In step1570 the macro cell base station determines the second group of smallcell base stations based on the last known or average strength, e.g.,reference signal received quality (RSRQ) of the macro cell as reportedby the second UE. In step 1572 the macro cell base station determinesthe second group of small cell base stations based on the number of UEsrequiring paging. In step 1574 the macro cell base station determinesthe second group of small cell base stations based on the number ofsmall cells under the macro cell's coverage area. In step 1576 the macrocell base station determines the second group of small cell basestations based on received radio network planning data feeddata/information, e.g. via Operations, Administration and Maintenance(OAM), updated via Automatic Neighbor Relations (ANR) and/or viaSelf-Organizing Networks (SON). In some embodiments, step 1576 includesstep 1578 in which the macro cell base station determines the secondgroup of small cell base stations based on a received provision list ofsmall cells under its hierarchy. In step 1580 the macro cell basestation determines the second group of small cell base stations based onreceived UE reports including second UE reports. Operation proceeds fromstep 1556 to step 1582, if the determined second group of small cellbase stations includes at least one small cell base station; otherwisestep 1582 is bypassed.

In step 1582 the macro cell base station sends the paging request topage the second UE to each of the small cell base stations in thedetermined second group of small cell base stations. Step 1582 includesstep 1584 and may, and sometimes does, include additions steps, e.g.step 1586, e.g., depending upon the number of small cell base stationsin the determined second group of small cell base stations. In step 1584the macro cell base station sends a paging request to page the second UEto a first small cell base station in said determined second group ofsmall cell base stations. In step 1586 the macro cell base station sendsa paging request to page the second UE to an Mth small cell base stationin said determined second group of small cell base stations. Operationproceeds from step 1582, via connecting node D 1588 to step 1590, if themacro cell base station is one of the base stations in the determinedsecond set of base stations which are to attempt to page the second UE;otherwise, step 1590 is bypassed.

In step 1590 the macro cell base station attempts to page the second UE,e.g. during a time interval in which the determined second group ofsmall cell base stations attempts to page the second UE. Operationproceeds from step 1590 to step 1591, if the determined second group ofsmall cell base station includes at least one small cell base station;otherwise, step 1591 is bypassed.

In step 1591 the macro cell base station monitors for paging responsemessages from small cell base stations in said determined second groupof small cell base stations. Step 1591 is performed on an ongoing basis,e.g., for a predetermined time interval. Step 1591 may, and sometimesdoes include one or more iterations of step 1592. In step 1592 the macrocell base station receives a paging response message from a small cellbase station in said determined second group of small cell base stationsindicating one of: i) an attempt at the small cell base station to pagethe second UE device was successful or ii) an attempt at the small cellbase station to page the second UE device was unsuccessful. Step 1592may, and sometimes does includes step 1593.

In step 1593 the macro cell base station receives a response from asmall cell base station in said determined second group of small cellbase stations indicating that the paging attempt was unsuccessful andfurther indicating the reason for the paging attempt failure, e.g., i)the small cell base station was unable to transmit a paging signal topage the second UE because listen-before-talk (LBT) indicated theunavailability of unlicensed spectrum or ii) the second UE did notrespond to transmitted paging signals. Operation proceeds from step 1591to step 1594.

In step 1594 the macro cell base station determines whether the pagingattempt to page the second UE was successful or unsuccessful from theperspective of the macro base station. Operation proceeds from step 1594to step 15941.

In step 15941 the macro cell base station sends to a network node, e.g.,to an AMF, a paging response message indicating one of success orfailure to page the second UE. Step 15941 includes steps 1595, 1596,1597, 1598, and 1599.

In step 1595 if the determination is that the paging attempt to page thesecond UE was successful, then operation proceeds from step 1595 to step1596; however, if the determination is that the paging attempt to pagethe second UE was unsuccessful then operation proceeds from step 1595 tostep 1597.

In step 1596, the macro cell base station sends, e.g., to the AMF, apaging response message indicating that the paging attempt to page thesecond UE was successful. In some embodiments, step 1596 is bypassed.

Returning to step 1597, in step 1597 the macro cell base stationdetermines if at least one of the base stations in the second set ofbase stations determined to attempt to page the second UE intended touse unlicensed spectrum for the paging attempt. If the determination isthat none of the base stations in the second set of base stationsdetermined to attempt to page the second UE intended to use unlicensedspectrum for the paging attempt, then operation proceeds from step 1597to step 1598 in which the macro cell base station sends, e.g. to theAMF, a paging response message indicating that the attempt to page thesecond UE failed. In some embodiments, the paging response message ofstep 1598 indicates that the paging attempt failed because the second UEdid not respond to transmitted paging signals.

If the determination is that at least one of the base stations in thesecond set of base stations determined to attempt to page the second UEintended to use unlicensed spectrum for the paging attempt, thenoperation proceeds from step 1597 to step 1599 in which the macro cellbase station sends, e.g. to the AMF, a paging response messageindicating that the attempt to page the second UE failed, said pagingresponse message indicating the reason or reason(s) that the pagingattempt failed, e.g., unavailability of unlicensed spectrum and/or thesecond UE did not respond to transmitted paging signals. Operationproceeds from step 1596, step 1598 or step 1599, via connecting node E1552, to step 1554, in which the macro cell base station receivesanother paging request to page the second UE. Operation proceeds fromstep 1554 to step 1556. During different iterations of steps 1556 themacro cell base station may, and sometime does, determine a differentsecond set of base stations and a different second group of small cellbase stations which are to attempt to page the second UE, e.g. dependingupon current conditions.

The flowchart 1500 of FIG. 15 has described exemplary steps for pagingrelated operated for paging a first UE (see FIG. 15A and FIG. 15B) andexemplary steps for paging related operations for paging a second UE(See FIG. 15C and FIG. 15D), where the first UE and the second UE aredifferent devices in the communications system. It should beappreciated, that the macro cell base station can, and sometimes does,page additional UEs, e.g., a third UE, a fourth UE, etc., and the stepsof FIG. 15A/FIG. 15B or FIG. 15C/FIG. 15D are adapted and repeated foreach additional UE being paged.

In some embodiments, the exemplary method of flowchart 1500 of FIG. 15is implemented by communications devices in communications system 1600of FIG. 15; the macro cell base station, e.g., macro cell BS 1 1604,uses licensed spectrum; and the small cell base stations, e.g., smallcell base station 1 1608, use unlicensed spectrum.

In some embodiments, a small cell base station, e.g., small cell basestation 1 1608, is within a coverage area, e.g., coverage area 1605, ofthe macro cell base station, e.g., macro cell BS 1 1604, and fills in adead zone in the macro cell base station coverage area. In someembodiments, a small cell base station, e.g., small cell base station 31612 has a coverage area, e.g., coverage area 1613 which partiallyoverlaps the macro cell base station coverage area, e.g., 1605 and thecoverage area, e.g., coverage area 1607, of another (macro cell) basestation, e.g., macro cell base station 2 1606, said small cell basestation, e.g., small cell base station 3 1612, being at a locationcorresponding to a boundary area between macro cell base stations, e.g.,macro cell BS 1 1604 and macro cell BS 2 1606.

In some embodiments, the exemplary method of flowchart 1500 of FIG. 15is implemented by communications devices in communications system 3000of FIG. 30; the macro cell base station uses unlicensed spectrum, e.g.,macro cell BS 1 1604′ uses unlicensed spectrum F1; and the small cellbase stations use unlicensed spectrum, e.g., small cell base station 11608′ uses unlicensed spectrum F3, where F1 is different from F1. Insome such embodiments, a small cell base station, e.g., small cell basestation 1 1608′, is within a coverage area, e.g., coverage area 1605, ofthe macro cell base station, e.g., macro cell BS 1 1604′, and fills in adead zone in the macro cell base station coverage area.

In some embodiments, said the determining of step 1506 is based on atleast two of: i) historical cell information (1510); ii) first UEmobility pattern information (1512); iii) signal measurement reportscommunicated by the first UE to the first base station (1514); iv)channel quality information feedback (1516) communicated by the first UEto the first base station or another network device, v) physicaldownlink control channel load on a physical downlink control channel(PDCCH) at the first base station (1518), vi) a received signal strength(1520) (e.g., last known or average received signal strength) of asignal (e.g., RSRQ signal) transmitted by the first base station asreported to the first base station to by the first UE, vii) number(1522) of UEs requiring paging, vii) a number (1524) of small cellsunder a coverage area of the first base station, viii) radio networkplanning data (1526) and ix) received UE reports (1530).

In some embodiments, the determining of step 1506 is based on at leastthree of: i) historical cell information (1510); ii) first UE mobilitypattern information (1512); iii) signal measurement reports communicatedby the first UE to the first base station (1514); iv) channel qualityinformation feedback (1516) communicated by the first UE to the firstbase station or another network device (1518), v) physical downlinkcontrol channel load on a physical downlink control channel (PDCCH) atthe first base station, vi) a received signal strength (1520) (e.g.,last known or average received signal strength) of a signal (e.g., RSRQsignal) transmitted by the first base station as reported to the firstbase station to by the first UE, vii) number (1522) of UEs requiringpaging, vii) a number (1524) of small cells under a coverage area of thefirst base station, viii) radio network planning data (1526) and ix)received UE reports (1530).

In some embodiments, the exemplary method includes communicating, e.g.,between a small cell base station and a macro cell base station, pagingsuccess response messages and paging failure response messages, e.g. theexemplary method uses a paging response message format such as shown inexemplary paging response message 3200 of FIG. 32, which includes apaging attempt success/fail indicator value field 3208 and, in the caseof failure, further includes a paging fault code indicator value field3210.

In some embodiments, the exemplary method includes communicating pagingfailure response messages but does not include communicating pagingsuccess response messages, e.g., the exemplary method uses a pagingresponse message format such as shown in exemplary paging responsemessage 3300 FIG. 33 or exemplary paging response message 3400 of FIG.34. In the example of FIG. 33 the paging failure response message 3300includes a paging fault code indicator value field 3310, whichcommunicates which one of a plurality of different types of faultsoccurred to result in paging failure, e.g., i) UE did not respond to apaging signal transmitted by the small cell base station or ii)unlicensed spectrum was currently unavailable (LBT failed to clear) sothe small cell base station did not transmit a paging signal.

In an embodiment implementing the exemplary paging response message 3400of FIG. 34, the paging failure response message 3400 is sent by thesmall cell base station to the macro cell base station if the pagingattempt at the small cell base station to page the UE failed due tounavailability of unlicensed spectrum (LBT failed to clear), but thesmall cell base station does not send a paging failure response messageto the macro cell base station when the paging failure is due to noresponse from the UE.

In some embodiments, the paging response message received by the macrocell base station from a small cell base station may, and sometimesdoes, indicates a paging failure and further indicates the reason forthe paging attempt failure (see step 1543). In some such embodiments,the paging response message includes information (e.g., a failure causecode—see exemplary paging response messages 3200, 3300 of FIG. 32, 33,respectively) indicating the reason for the paging attempt failure whichindicates one of: i) unavailability of the unlicensed spectrum (LBTfails to clear) resulting in no paging signal transmitted by the firstsmall cell base station or ii) no response received from the first UEdevice in response to a transmitted paging signal.

In some embodiments, the paging response message received by the macrocell base station from the first small cell base station may, andsometimes does, indicates a paging failure and indicates (explicitly(e.g., via a fail code included in the message—see exemplary message3200 of FIG. 32 and exemplary message 3300 of FIG. 33) or implicitly(e.g., via transmission of a paging response message—see exemplarymessage 3400 of FIG. 34) the reason for the paging attempt failure isunavailability of the unlicensed spectrum (LBT fails to clear) resultingin no paging signal being transmitted by the first small cell basestation.

In various embodiments, the steps of FIGS. 15A and 15B may be, andsometimes are, performed multiplied times. In one example, duringdifferent iterations of the steps of FIG. 15A and FIG. 15B, the macrocell base station selects different sets of base station which are toattempt to page the first UE. For example, during a second iteration theselected set of base stations which are to attempt to page the UEincludes at least one new base station which was not selected in thefirst iteration.

In various embodiments, the section, by a macro cell base station, of aset of base stations which are to attempt to page a particular UE is UEspecific. For example, the macro cell base station selects a first setof base stations which are to page a first UE and a second set of basestations which are to page a second UE, and the first and second setsmay be, and sometimes are different, e.g. even though the first andsecond UEs may be located in the same approximate location within themacro cell and are to be paged at the same approximate time.

FIG. 16 is a drawing of an exemplary communications system 1600 inaccordance with an exemplary embodiment. Exemplary communications system1600 includes an access and mobility function (AMF) device 1602, whichis a network node, a plurality of macro cell base stations (macro cellbase station 1 (BS1) 1604, e.g., gNBM1 using licensed spectrum, macrocell base station 2 (BS2) 1606, e.g., gNBM2 using licensed spectrum, anda plurality of small cell base stations (small cell base station 1 (BS1)1608, e.g., gNBS1 using unlicensed spectrum, small cell base station 2(BS2) 1610, e.g., gNBS2 using unlicensed spectrum, small cell basestation 3 (BS3) 1612, e.g., gNBS3 using unlicensed spectrum, small cellbase station 4 (BS4) 1614, e.g., gNBS4 using unlicensed spectrum, smallcell base station 5 (BS5) 1616, e.g., gNBS5 using unlicensed spectrum)coupled together as shown in FIG. 16. AMF device 1602 is coupled tomacro cell BS 1 1604 via communications link 1618. AMF device 1602 iscoupled to macro cell BS 2 1606 via communications link 1620. Macro basestation 1 1604 is coupled to small cell base stations (small cell basestation 1 1608, small cell base station 2 1610, small cell base station3 1612) via communications links (1622, 1624, 1626), respectively. Macrobase station 2 1606 is coupled to small cell base stations (small cellbase station 3 1612, small cell base station 4 1614, small cell basestation 5 1616) via communications links (1628, 1630, 1632),respectively. AMF device 1602 is coupled to other network nodes and/orthe Internet via communications link 1646.

Macro cell base station 1 1604 has a wireless coverage area representedby dashed line circle 1605. Macro cell base station 2 1606 has awireless coverage area represented by dashed line circle 1607. Each ofthe small cell base stations (small cell base station 1 1608, small cellbase station 2 1610, small cell base station 3 1612, small cell basestation 4 1614, small cell base station 5 1616), has a correspondingwireless coverage area represented by dashed line circles (1609, 1611,1613, 1615, 1617), respectively.

Small cell base station 1 1608 and small cell base station 2 1610 arelocated inside the wireless coverage area 1605 corresponding to macrocell base station 1 1604. In some embodiments, the small cell basestations (1608, 1610) are intentionally located to provide wirelesscoverage for dead zones within the macro base station wireless coveragearea 1605.

Small cell base station 4 1614 and small cell base station 5 1616 arelocated inside the wireless coverage area 1607 corresponding to macrocell base station 2 1606. In some embodiments, the small cell basestations (1614, 1616) are intentionally located to provide wirelesscoverage for dead zones within the macro base station wireless coveragearea 1607.

Small cell base station 3 1612 has a wireless coverage area 1613, whichpartially overlaps the wireless coverage area (1605, 1607). Thus smallcell base station 3 1612 is intentionally located to provide wirelesscoverage in a gap region between the coverage provided by the two macrobase stations (1604, 1606).

The exemplary communications system 1600 further includes a plurality ofuser equipment (UE) devices (UE 1 1634, UE 2 1636, UE 3 1638, UE 4 1640,UE 5 1642, UE 6 1644) which may move throughout the communicationssystem 1600 and communicate via different base stations at differenttimes.

Exemplary communications system 1600 supports novel paging methods andapparatus in accordance with various exemplary embodiments. Thecommunications system of FIG. 16 supports the exemplary methods offlowchart 1500 of FIG. 15 and flowchart 2500 of FIG. 25.

FIGS. 17-24 are used to illustrate exemplary steps and exemplarysignaling, which may be performed with regard to system 1600 of FIG. 16in accordance with various exemplary embodiments. Drawing 1700 of FIG.17 will now be described. In drawing 1700 of FIG. 17, in step 1702 theAMF device 1602 generates and sends paging request message 1703 to macrocell base station 1 1604. Paging request message 1703 communicates arequest that UE 2 1636 be paged. In step 1704, macro cell BS 1 1604receives paging request message 1703 and recovers the communicatedinformation. UE2 1636 has previously moved to its current location, fromits previous known location as indicated by arrow 1701.

In step 1706 macro cell BS 1 1604 determines to page UE 2 1636 usingmacro BS 1 1604, small cell base station 1 1608 and small cell basestation 3 1612. Thus the determined set of base stations to be used topage UE 2 1636 is the set of {macro BS 1 1604, small cell BS 1 1608,small cell BS 3 1612}, and the determined group of small cell basestations to be used to page UE 2 1636 is the group of: small cell BS 11608 and small cell BS 3 1612.

In step 1708 macro cell BS 1 1604 generates and sends paging requestmessage 1710 to small cell BS1 1608, requesting that UE 2 1636 be paged.In step 1712 small cell BS 1 1608 receives paging request message 1710and recovers the communicated information.

In step 1714 macro cell BS 1 1604 generates and sends paging requestmessage 1716 to small cell BS3 1612, requesting that UE 2 1636 be paged.In step 1718 small cell BS 3 1612 receives paging request message 1716and recovers the communicated information.

Drawing 1800 of FIG. 18 will now be described. In drawing 1800 of FIG.18, in step 1804 small cell base station 1 1608, which uses unlicensedspectrum and which has been requested to page UE2 1636, performs alisten-before-talk operation, which determines that the unlicensedspectrum is currently unavailable; therefore, small cell BS 1 1608 isunable to transmit the requested paging signal. In step 1806 small cellbase station 3 1612, which uses unlicensed spectrum and which has beenrequested to page UE2 1636, performs a listen-before-talk operation,which determines that the unlicensed spectrum is currently unavailable;therefore, small cell BS 3 1612 is unable to transmit the requestedpaging signal. In step 1808 macro cell base station 1 1604, which useslicensed spectrum, transmits a paging signal directed to UE2 1636. Instep 1810 macro cell base station 1 1604 monitors for a response signal,e.g. a RRC connection establishment signal, from UE 2 1636 in responseto the transmitted paging signal, but does not receive a reply since UE2 1636 is currently outside coverage area 1605.

Drawing 1900 of FIG. 19 will now be described. In drawing 1900 of FIG.19, in step 1902 small cell base station 3 1612 generates and sendspaging response message 1904 to macro cell base station 1 1604. Pagingresponse message 1904 includes information indicating that the attemptto page UE 2 was a failure and that small cell base station 3 1612 didnot transmit a paging message to page UE 2 because the spectrum wasunavailable. In step 1906 macro cell BS 1 1604 receives paging responsemessage 1904 and recovers the communicated information. In step 1908small cell base station 1 1608 generates and sends paging responsemessage 1910 to macro cell base station 1 1604. Paging response message1910 includes information indicating that the attempt to page UE 2 was afailure and that small cell base station 1 1608 did not transmit apaging message to page UE 2 because the spectrum was unavailable. Instep 1912 macro cell BS 1 604 receives paging response message 1910 andrecovers the communicated information.

In step 1914 macro cell BS 1 1604 generates and sends paging responsemessage 1916 to AMF device 1602. Paging response message 1916 includesinformation indicating that the UE 2 paging attempt was a failure andthat the paging message was not sent in unlicensed spectrum because theunlicensed spectrum was unavailable, e.g. in each of the small cells inwhich paging was attempted. In some embodiments, the paging responsemessage may, and sometime does, includes failure type information on aper base station basis, e.g., a per small cell base station basis.

FIGS. 20 and 21 provide an exemplary alternative scenario, e.g., apaging attempt success scenario, to the example of FIGS. 18 and 19. FIG.20 may be considered a continuation from FIG. 17. Drawing 2000 of FIG.20 will now be described. In drawing 2000 of FIG. 20, in step 2002 macrocell base station 1 1604, which uses licensed spectrum, transmits apaging signal directed to UE2 1636. In step 2003 macro cell base station1 1604 monitors for a response signal, e.g., a RRC connectionestablishment signal, from UE 2 1636 in response to the transmittedpaging signal, but does not receive a reply since UE 2 1636 is currentlyoutside coverage area 1605. In step 2004 small cell base station 1 1608,which uses unlicensed spectrum and which has been requested to page UE21636, performs a listen-before-talk operation, which determines that theunlicensed spectrum is currently available; therefore, small cell BS 11608 transmits the requested UE 2 paging signal. In step 2005 small cellBS 1 1608 monitors for a response signal, e.g., a RRC connectionestablishment signal, from UE 2 1636 in response to the transmittedpaging signal, but does not receive a reply since UE 2 1636 is currentlyoutside coverage area 1609. In step 2006 small cell base station 3 1612,which uses unlicensed spectrum and which has been requested to page UE21636, performs a listen-before-talk operation, which determines that theunlicensed spectrum is currently available; therefore, small cell BS 31612 transmit the requested paging signal. In step 2008 UE 2 receivesthe paging signal and, in response generates and sends a responsesignal, e.g., a RRC connection establishment signal, to small cell basestation 3 1612. Small cell base station 3 1612, which has beenmonitoring for a response to its transmitted paging signal in step 2007,detects the response signal, e.g., the RRC connection establishmentsignal, from UE 2 1636, as indicated in step 2009.

Drawing 2100 of FIG. 21 will now be described. In drawing 2100 of FIG.21, in step 2102 small cell base station 1 1608 generates and sendspaging response message 2104 to macro cell base station 1 1604. Pagingresponse message 2104 includes information indicating that the attemptto page UE 2 was a failure and that small cell base station 1 1608transmitted a paging message to page UE 2 but did not receive a responsefrom UE 2. In step 2106 macro cell BS 1 1604 receives paging responsemessage 2104 and recovers the communicated information. In step 2108small cell base station 3 1612 generates and sends paging responsemessage 2110 to macro cell base station 1 1604. Paging response message2110 includes information indicating that the attempt to page UE 2 was asuccess. In step 2112 macro cell BS 1 1604 receives paging responsemessage 2110 and recovers the communicated information.

In step 2114 macro cell BS 1 1604 generates and sends paging responsemessage 2116 to AMF device 1602, e.g., based on the combined pagingattempt results of the paging attempted by the selected set of basestations. Paging response message 2116 includes information indicatingthat the UE 2 page attempt was a success.

FIGS. 22-24 illustrate another example of paging related steps andsignaling in accordance with an exemplary embodiment. Drawing 2200 ofFIG. 22 will now be described. In drawing 2200 of FIG. 22, in step 2202the AMF device 1602 generates and sends paging request message 2203 tomacro cell base station 1 1604. Paging request message 2203 conveysinformation indicating that paging of UE 4 1640 is requested. In step2204 macro cell BS 1 1504 receives the paging request message 2203 andrecovers the communicated information. Dotted line arrow 2201 indicatesthe motion of UE 4, e.g., from the last known position fix to itscurrent location. Macro cell BS 1 1604 determines to page UE 4 usingmacro BS 1 1604 and using small cell base station 2 1610, which is closeto the last known position fix for UE 4 1640. Thus macro cell basestations determines that the set of base stations, e.g. under itscontrol, which are to attempt paging of UE 4 1640 is {macro cell BS 11604 and small cell BS 2 1610}, and the group of small cells, e.g.,under its hierarchy, which are to attempt paging of UE 4 is a group of 1small cell BS, which is small cell BS 2 1610. In step 2206 macro cell BS1 1604 generates and sends paging request message 2208 to small cell BS2 1610 requesting that UE 4 1640 be paged. In step 2210 small cell BS 21610 receives the paging request message 2208 and recovers thecommunicated information.

Drawing 2300 of FIG. 23 will now be described. In drawing 2300 of FIG.23, in step 2302 macro cell BS 1 1604 generates and transmits UE 4paging signals and in step 2303 macro cell BS 1 1604 monitors for aresponse signal, e.g., a RRC connection establishment signal, from UE 4;however, UE 4 1640 is currently outside coverage area 1605; therefore,macro cell BS 1 1604 does not receive a response signal from UE 4 1640.In step 2305, small cell BS 2 1610 performs a listen-before-talkoperation, determines that the unlicensed spectrum is available, andtransmits UE 4 paging signals. In step 2305 small cell BS 2 1610monitors for a response signal, e.g., a RRC connection establishmentsignal, from UE 4; however, UE 4 1640 is currently outside coverage area1611; therefore, small cell BS 2 1610 does not receive a response signalfrom UE 4 1640.

Drawing 2400 of FIG. 24 will now be described. In drawing 2400 of FIG.24, in step 2402 small cell base station 2 1610 generates and sendspaging response message 2404 to macro cell base station 1 1604. Pagingresponse message 2404 includes information indicating that the attemptto page UE 4 was a failure and that small cell base station 2 1610transmitted a paging message to page UE 4 but did not receive a responsefrom UE 4. In step 2406 macro cell BS 1 1604 receives paging responsemessage 2404 and recovers the communicated information. In step 2408macro cell BS 1 1604 generates and sends paging response message 2410 toAMF device 1602. Paging response message 2410 includes informationindicating that the UE 4 page attempt was a failure and that pagingsignals were transmitted by each of the selected base stations but thatno paging response was received from UE 4. In step 2312 the access andmobility function device 1602 receives paging response message 2410 andrecovers the communicated information. The AMF device uses thecommunicated information in determining a paging escalation strategy.For example, since the macro cell BS 1 1604 controlled paging wasunsuccessful and paging signals were transmitted in each of the selectedsmall cell base station's under macro cell BS 1's control, the AMF 1602may, and sometimes does, decide to send a paging request to page UE 41642 to macro cell BS 2 1606.

FIG. 25 is a flowchart 2500 of an exemplary method of operating a smallcell base station in accordance with an exemplary embodiment. The smallcell base station implementing the method of flowchart 2500 is, e.g.,one of the small cell base stations (small cell base station 1 1608,small cell base station 2 1610, small cell base station 3 1612, smallcell base station 4 1614, small cell base station 5 1616) of system 1600of FIGS. 16-24, or one of the small cell base stations (small cell basestation 1 1608′, small cell base station 2 1610′, small cell basestation 3′ 1612′, small cell base station 4 1614′, small cell basestation 5 1616′) of system 3000 of FIG. 30, or one of the small cellbase stations (small cell base station 1 1608″, small cell base station2 1610″, small cell base station 3 1612″, small cell base station 41614″, small cell base station 5 1616″) of system 3100 of FIG. 31.

Operation of the exemplary method starts in step 2502, in which thesmall cell base station is powered on and initialized. Operationproceeds from step 2502 to step 2504. In step 2504 the small cell basestation receives, e.g., from a macro cell base station, a paging requestto page a UE, e.g., a first UE. Operation proceeds from step 2504 tostep 2506.

In step 2506, if the small cell base station is using unlicensedspectrum, then operation proceeds from step 2506 to step 2508. However,if the small cell base station is using licensed spectrum, thenoperation proceeds from step 2506 to step 2512.

Returning to step 2508, in step 2508 the small cell base stationperforms a listen-before-talk (LBT) operation to determine if theunlicensed spectrum is available to use to transmit a paging signal topage the UE. Operation proceeds from step 2508 to step 2510.

In step 2510, if the determination of step 2508 is that the unlicensedspectrum is currently available to be used by the small cell basestation then, operation proceeds from step 2510 to step 2512. However,if the determination of step 2508 is that the unlicensed spectrum iscurrently unavailable to be used by the small cell base station, thenoperation proceeds from step 2510 to step 2524.

Returning to step 2512, in step 2512 the small cell base stationtransmits a paging signal directed to the UE, e.g., for a predeterminedtime interval and/or for a predetermined number of times, to page theUE. Operation proceeds from step 2512 to step 2514.

In step 2514 the small cell base station monitors for a response signalfrom the UE, e.g. a RRC connection establishment signal, in response tothe transmitted paging signal. Step 2514 may, and sometimes does,include step 2516, in which the small cell base station receives aresponse signal, e.g., a RRC connection establishment signal, from theUE in response to the transmitted paging signal of step 2512. Operationproceeds from step 2516 to step 2520. In step 2520 the small cell basestation decides to include a paging success indicator in a pagingresponse message to be generated. Operation proceeds from step 2520, viaconnecting node A 2528 to step 2536 of step 2534.

Returning to step 2514, operation proceeds from step 2514 to step 2518.In step 2518 the small cell base station determines if a criteria formaximum paging transmission attempts has been reached without receivinga response from the UE. If the determination of step 2518 is that thecriteria for maximum paging attempts has not been reached then operationproceeds from step 2518 to step 2512, in which the small cell basestation continues to transmit a paging signal to page the UE. However,if the determination of step 2518 is that the criteria for maximumpaging attempts has been reached, then operation proceeds from step 2518to step 2522. In step 2522 the small cell base station decides toinclude a paging failure indicator in a paging response message to begenerated, wherein the paging failure indicator indicates that reasonfor the paging failure is that the UE did not respond to the pagingsignals transmitted by the small cell base station. Operation proceedsfrom step 2522, via connecting node B 2530, to step 2538 of step 2534.

Returning to step 2524, in step 2524, the small cell base stationdetermines if either of: i) the maximum time limit for performing listenbefore talk (LBT) checks on the unlicensed spectrum for this pagingmessage has been reached, or ii) the paging message exceeded theallowable time for a paging message to be in the base station buffer,has been satisfied. If the determination of step 2524 is that neither oftest conditions: i) the maximum time limit for performing listen beforetalk (LBT) checks on the unlicensed spectrum for this paging message hasbeen reached, or ii) the paging message exceeded the allowable time fora paging message to be in the base station buffer, has been satisfied,then operation proceeds from step 2524 to the input of step 2508, foranother LBT operation. However, if the determination of step 2524 isthat either of test conditions: i) the maximum time limit for performinglisten before talk (LBT) checks on the unlicensed spectrum for thispaging message has been reached, or ii) the paging message exceeded theallowable time for a paging message to be in the base station buffer,has been satisfied, then operation proceeds from step 2524 to step 2525in which the small cell base station decides to transmit a pagingfailure response message. Operation proceeds from step 2525 to step2526.

In step 2526 the small cell base station decides to include a pagingfailure indicator in a paging response message, e.g., a paging failureresponse message, to be generated, and the indicator indicates that thereason for failure is that the unlicensed spectrum was unavailable sothe small cell base station was unable to transmit paging signals topage the UE. Operation proceeds from step 2526, via connecting node C2532, to step 2540 of step 2534.

In step 2534, the small cell base station generates a paging responsemessage, said paging response message indicating one of: i) an attemptat the small cell base station to page the UE was successful or ii) anattempt at the small cell base station to page the UE was unsuccessful.Step 2534 includes alternative steps 2536, 2538 and 2540. In step 2536the small cell base station generates a paging response messageindicating that the paging attempt to page the UE was successful. Instep 2538 the small cell base station generates a paging responsemessage indicating that the paging attempt to page the UE was a failureand the reason for the failure is that the UE did not respond to thetransmitted paging signals. In step 2540 the small cell base stationgenerates a paging failure response message which communicates, e.g.,explicitly or implicitly, that the paging attempt by the small cell basestation to page the UE failed and the reason for the paging attemptfailure is unavailability of the unlicensed spectrum resulting in nopaging signal being transmitted by the small cell base station. In someembodiments, step 2540 includes step 2541 in which the small cell basestation generates a paging response message indicating that the pagingattempt to page the UE was a failure and the reason for the failure isthat the unlicensed spectrum was unavailable so the small cell basestation was unable to transmit the paging signal.

Operation proceeds from step 2534 to step 2542 in which the small cellbase station sends the generated paging response message to the macrocell base station, e.g., the small cell base stations transmits thegenerated paging response message, with the generated paging responsemessage being communicated along a backhaul communications path anddirected to the macro cell base station as the intended destination ofthe message. Operation proceeds from step 2542, via connecting node D2544 to step 2504, in which the small cell base station receives anotherrequest to page a UE. The requested UE may be the same UE as previouslyrequested or a different UE.

In some exemplary embodiments, the small cell base station does nottransmit a paging response message to the macro base station indicatingpaging success, and steps 2520 and 2536 are not performed. For example,in some embodiments, the UE's response to paging signal transmitted fromthe small cell base station, which was detected by the UE, is toestablish RRC connection with small cell the base station correspondingto the received paging signal, and then the UE starts NAS interaction,e.g., with an AMF, to transition to CONNECTED state. So, the small cellbase station, macro cell base station, and AMF will know that the pagingattempt to page the UE was successful.

In some embodiments, a small cell base station transmits a pagingresponse message which is a paging failure response message and themessage includes a failure cause code which identifies the failure arebeing one of: i) paging failure due to no response from the UE beingpaged or ii) paging failure due to unavailability of unlicensedspectrum.

In some exemplary embodiments, the small cell base station onlytransmits a paging response message to the macro cell base station, whenthe small cell base station is using unlicensed spectrum, and theunlicensed spectrum is not available, such that the small cell basestation cannot transmit paging signals to page the UE. In some suchembodiments, the paging response message is a paging failure responsemessage which implicitly indicates by its presence that the pagingattempt by the small cell base station to page the UE failed due tounavailable of the unlicensed spectrum. In some such embodiments, steps2522 and 2538 are not performed.

FIG. 26 is a drawing of an exemplary macro cell base station 2600, e.g.,a gNB or ng-eNB, in accordance with an exemplary embodiment. Exemplarymacro cell base station 2600 is, e.g., one of the macro cell basestations (1604, 1606) of system 1600 of FIGS. 16-24, one of the macrocell base stations (1604′, 1604′) of system 3000 of FIG. 30, one of themacro cell base stations (1604″, 1604″) of system 3100 of FIG. 31,and/or a macro cell base station implementing a method in accordancewith flowchart 1500 of FIG. 15.

Exemplary macro cell base station 2600 includes a processor 2602, e.g.,a CPU, a wireless interface 2604, a network interface 2606, e.g., awired or optical interface, an assembly of hardware components 2608,e.g., an assembly of circuits, and memory 2610 coupled together via bus2611 over which the various elements may interchange data andinformation.

Wireless interface 2604 includes a wireless receiver 2612 coupled toreceive antenna 2613, via which the macro cell base station 2600 mayreceive wireless signals, e.g., a response signal from a UE being paged.Wireless interface 2604 includes a wireless transmitter 2614 coupled totransmit antenna 2615, via which the macro cell base station 2600 maytransmit wireless signals, e.g., a paging signal to page a UE.

Network interface 2606 includes a receiver 2612 via which the macro cellbase station 2600 may receive signals, e.g., signals from network nodesand/or small cell base stations. Exemplary signals received via receiver2616 include a paging request from a network node, e.g., AMF device, topage a UE, and a paging response from a small cell base station. Networkinterface 2606 further includes a transmitter 2618 via which the macrocell base station 2600 may transmit signals, e.g., send signals tonetwork nodes and/or to small cell base stations. Exemplary signalstransmitted via transmitter 2618 include a paging response signal to anetwork node, e.g., an AMF, and a paging request signal to a small cellbase station.

Memory 2610 includes a control routine 2620, an assembly of components2622, e.g., an assembly of software components, and data/information2624. Data/information 2624 includes paging related informationcorresponding to one or more UEs (first UE paging information 2626, . .. , Nth UE paging information 2628). First UE paging information 2626includes a received paging request to page a first UE, and a determinedfirst set of base stations to attempt to page the first UE 2632. Thedetermined first set of base stations to attempt to page the first UE2632 includes a determined first group of small cell base stations whichare to attempt to page the first UE 2632. First UE paging information2626 may, and sometimes does, include a generated paging request to pagethe first UE to be sent to a first small cell base station in said firstgroup of small cell base stations 2636. First UE paging information 2626may, and sometimes does include a generated paging request to page thefirst UE to be sent to an Nth small cell base station in said firstgroup of small cell base stations 2638.

First UE paging information 2626 further includes a generated pagingsignal 2640 to be transmitted by transmitter 2614 to page the first UE.First UE paging information 2626 may, and sometimes does, include adetected paging response signal from the first small cell base stationin said first group of small cell base stations 2642. Detected pagingresponse signal from the first small cell base station 2642 includes UEidentification information 2644, and paging result information 2644,e.g., indicating success or fail. In some embodiments, detected pagingresponse signal from the first small cell base station 2642 may, andsometimes does, include a fail code 2648 indicating the reason for thepaging failure, e.g., i) the first small cell base station was unable totransmit the paging signal because the unlicensed spectrum wasunavailable or ii) the UE did not respond to the paging signaltransmitted by the first small cell base station. First UE paginginformation 2626 may, and sometimes does, include a detected pagingresponse signal from the Nth small cell base station in said first groupof small cell base stations 2650.

First UE paging information 2626 further includes a generated pagingresponse 2652 to be sent to the network node, e.g., to the AMF, inresponse to the received paging request 2630. Generated paging response2652 includes UE ID information 2654 and paging result information 2656,e.g., indicating paging success or paging failure. Generated pagingresponse 2652 may, and sometimes does, include fault information 2658,e.g., a fault code or codes identifying the reason or reasons for thepaging failure, e.g., unlicensed spectrum was unavailable or the UE didnot respond to transmitted paging signals.

First UE paging information 2626 further includes historical cellinformation submitted by the first UE, e.g., during RRC connectionestablishment and/or during RRC Connection release 2660, first UEmobility pattern information 2662, measurement reports for the first UE2664, channel quality information (CQI) feedback for potential carrieraggregation (CA) target small cells 2666, physical downlink controlchannel (PDCCH) loading due to paging 2668, radio network planninginformation 2670, e.g., including a provision list identifying smallcell base station under the hierarchy of the macro cell base station2600, received signal received quality (RSRQ) reported by the first UE2672, e.g., with regard to reference signal transmitted from macro cellbase station 2600, a number of UE requiring paging 2674, and a number ofsmall cells under the macro coverage 2674 of the macro cell base station2600.

FIG. 27 is a drawing of an exemplary small cell base station 2700, e.g.,a gNB or ng-eNB, in accordance with an exemplary embodiment. Exemplarysmall cell base station 2700 is, e.g., one of the small cell basestations (1608, 1610, 1612, 1614, 1616) of system 1600 of FIGS. 16-24,one of the small cell base stations (1608′, 1610′, 1612′, 1614′, 1616′)of system 3000 of FIG. 30 or one of the small cell base stations (1608′,1610″, 1612″, 1614″,1616″) of system 3100 of FIG. 31 and/or a small cellbase station implementing a method in accordance with flowchart 2500 ofFIG. 25.

Exemplary small cell base station 2700 includes a processor 2702, e.g.,a CPU, a wireless interface 2704, a network interface 2706, e.g., awired or optical interface, an assembly of hardware components 2708,e.g., an assembly of circuits, and memory 2710 coupled together via bus2711 over which the various elements may interchange data andinformation.

Wireless interface 2704 includes a wireless receiver 2712 coupled toreceive antenna 2713, via which the small cell base station 2700 mayreceive wireless signals, e.g., a paging response from a UE being paged.Wireless interface 2704 includes a wireless transmitter 2714 coupled totransmit antenna 2715, via which the small cell base station 2700 maytransmit wireless signals, e.g., a paging signal to page a UE.

Network interface 2706 includes a receiver 2712 via which the small cellbase station 2700 may receive signals, e.g., signals from network nodesand/or from macro cell base stations. Exemplary signals received viareceiver 2716 include a paging request from a macro cell base station topage a UE. Network interface 2606 further includes a transmitter 2718via which the small cell base station 2700 may transmit signals, e.g.,signals to network nodes and/or to macro cell base stations. Exemplarysignals transmitted via transmitter 2718 include a paging responsesignal to a macro cell base station.

Memory 2710 includes a control routine 2720, an assembly of components2722, e.g., an assembly of software components, and data/information2724. Data/information 2724 includes a received paging request from amacro cell base station to page a UE 2726, listen-before-talk results2728 including an unlicensed spectrum availability determination 2730.In some embodiments, data information 2724 includes one or both of: agenerated paging signal 2732 to be transmitted, via wireless transmitter2714, to page the UE, and a received paging response from the UE 2734.

Data/information 2724 further includes a generated paging responsesignal 2736 to be sent to the macro cell BS in response to the receivedpaging request 2726. Generated paging response signal 2736 includes UEID information 2738 and paging result 2740, e.g., information indicatingpaging success or paging failure. Generated paging response signal 2736may, and sometimes does, include a fail code or codes 2742, indicatingthe reason for the paging failure, e.g., i) unable to transmit thepaging signal because the unlicensed spectrum was unavailable or ii) theUE did not respond to transmitted paging signals.

Data/information 2724 further includes spectrum information 2744, e.g.,information identifying the unlicensed spectrum being used by the smallcell base station or information identifying the licensed spectrum, e.g.particular licensed spectrum band or sub-band being used by the smallcell base station. In some embodiments, in which the small cell basestation uses licensed spectrum, the small cell base station uses adifferent frequency band or different frequency sub-band than is used bythe macro cell base station. Data/information 2724 further includestiming structure information 2746. In some embodiments, the timingstructure information 2746 includes information indicating when pagingsignals are to be transmitted.

FIG. 28, comprising the combination of FIG. 28A and FIG. 28B, is adrawing of an exemplary assembly of components 2800, comprising thecombination of Part A 2801 and Part B 2803, which may be included in amacro base station in accordance with an exemplary embodiment. Forexample, assembly of components 2800 is included in any of the macrocell base stations (1604, 1606) of FIG. 16-24, in any of the macro cellbase stations (1604′, 1606′) of FIG. 30, in any of the macro cell basestations (1604″, 1606″) of FIG. 31 and/or in a macro cell base stationimplementing the method of flowchart 1500 of FIG. 15 and/or in macrocell base station 2600 of FIG. 26.

The components in the assembly of components 2800 can, and in someembodiments are, implemented fully in hardware within the processor2602, e.g., as individual circuits. The components in the assembly ofcomponents 2800 can, and in some embodiments are, implemented fully inhardware within the assembly of components 2608, e.g., as individualcircuits corresponding to the different components. In other embodimentssome of the components are implemented, e.g., as circuits, within theprocessor 2602 with other components being implemented, e.g., ascircuits within assembly of components 2608, external to and coupled tothe processor 2602. As should be appreciated the level of integration ofcomponents on the processor and/or with some components being externalto the processor may be one of design choice. Alternatively, rather thanbeing implemented as circuits, all or some of the components may beimplemented in software and stored in the memory 2610 of the macro cellbase station 2600, e.g., a gNB or ng-eNB, with the componentscontrolling operation of the base station to implement the functionscorresponding to the components when the components are executed by aprocessor, e.g., processor 2602. In some such embodiments, the assemblyof components 2800 is included in the memory 2610 as assembly ofcomponents 2622. In still other embodiments, various components inassembly of components 2800 are implemented as a combination of hardwareand software, e.g., with another circuit external to the processor 2602providing input to the processor 2602 which then under software controloperates to perform a portion of a component's function. While processor2602 is shown in the FIG. 26 embodiment as a single processor, e.g.,computer, it should be appreciated that the processor 2602 may beimplemented as one or more processors, e.g., computers.

When implemented in software the components include code, which whenexecuted by the processor 2602, configure the processor 2602 toimplement the function corresponding to the component. In embodimentswhere the assembly of components 2800 is stored in the memory 2610, thememory 2610 is a computer program product comprising a computer readablemedium comprising code, e.g., individual code for each component, forcausing at least one computer, e.g., processor 2602, to implement thefunctions to which the components correspond.

Completely hardware based or completely software based components may beused. However, it should be appreciated that any combination of softwareand hardware, e.g., circuit implemented components may be used toimplement the functions. As should be appreciated, the componentsillustrated in FIG. 28 control and/or configure the macro cell basestation 2600, or elements therein such as the processor 2602, to performthe functions of corresponding steps illustrated and/or described in themethod of one or more of the flowcharts, signaling diagrams and/ordescribed with respect to any of the Figures. Thus the assembly ofcomponents 2800 includes various components that perform functions ofcorresponding one or more described and/or illustrated steps of anexemplary method, e.g., steps of the method of flowchart 1500 of FIG. 15and/or described or shown with respect to any of the other figures.

Assembly of components 2800 includes a component 2804 configured tooperate the macro cell base station to receive, e.g., from an AMF, apaging request to page a UE, and a component 2806 configured todetermine a set of base stations what are to attempt to page the UE,said determined set of base stations including at least one basestation, said at least one base station including the macro cell basestation or a small cell base station. Component 2806 includes acomponent 2808 configured to determine a group of small cell basestations to which the paging request to page the UE is to communicated.Component 2808 includes one or more or all of: a component 2810configured to determine the group of small cell base stations base onhistorical cell information submitted by the UE to the macro cell basestation, e.g., during RRC connection establishment and/or during RRCconnection release, a component 2812 configured to determine the groupfof small cell base stations based on the UE's mobility pattern, e.g.,based on hysteresis information maintained by the macro cell basestation based on the UE's mobility pattern, a component 2814 configuredto determine the group of small cell base stations based on measurementreports for the UE, e.g., measurement reports received directly from theUE and/or measurement reports received indirectly from the UE, e.g., viaa small cell base station, a component 2816 configured to determine thegroup of small cell base stations based on channel quality informationfeedback for potential carrier aggregation (CA) target base stations, acomponent 2818 configured to determine the group of small cell basestations based on physical downlink control channel (PDDCH) channel loadon the macro cell due to paging operations, a component 2820 configuredto determine the group of small cell base stations based on the lastknown or average strength, e.g., RSRQ, of the macro cell base station asreported by the UE, a component 2822 configured to determine the groupof small cell base stations based on the number of UEs requiring paging,e.g., at a current instant of time, a component 2824 configured todetermine the group of small cell base station based on the number ofsmall cells under the macro cell's coverage, a component 2826 configuredto determine the group of small cell base stations based on receivedradio network planning data feed data/information, e.g., via OAM,updated via ANR and/or via SON, and a component 2830 configured todetermine the group of small cell base stations based on received UEreports, e.g., received UE reports from the particular UE which is to bepaged and, in some embodiments, UE reports from other UEs. Component2826 includes a component 2828 configured to determine the group ofsmall cell base stations based on a received provision list of smallcells under its hierarchy.

Assembly of components 2800 further includes a component 2832 configuredto operate the macro cell base station to send the paging request topage the UE to each of the small cell base stations in the determinedgroup of small cell base stations. Component 2832 includes a component2834 configured to operate the macro cell base station to send thepaging request to a first small cell base station in said determinedgroup of small cell base stations and a component 2836 configured tooperate the macro cell base station to send the paging request to an Nthsmall cell base station in said determined group of small cell basestations.

Assembly of components 2800 further includes a component 2840 configuredto operate the macro cell base station to attempt to page the UE, e.g.,during a time interval in which the determined group of small cell basestations attempts to page the UE, if the macro cell base station is oneof the base stations in the determined set of base stations which are toattempt to page the UE, and a component 2841 configured to operate themacro cell base station to monitor for paging response messages fromsmall cell base stations in said determined group of small cell basestations. Component 2841 includes a component 2842 configured to operatethe macro cell base station to receive a paging response message from asmall cell base station indicating one of: i) an attempt at the smallcell base station to page the UE was successful or ii) an attempt at thesmall cell base station to page the UE was unsuccessful. Component 2842includes a component 2843 configured to operate the macro cell basestation to receive a paging response message from a small cell basestation indicating that the paging attempt was unsuccessful and furtherindicating the reason for the paging attempt failure, e.g. the smallcell base station was unable to transmit a paging signal because thelisten before talk (LBT) operation indicated the unavailability ofunlicensed spectrum or because the UE did not respond to transmittedpaging signals.

Assembly of components 2800 further includes a component 2844 configuredto operate the macro cell base station to determine whether the pagingattempt to page the first UE was successful or unsuccessful, e.g., basedon combined results including, e.g. paging response messages from smallcell base stations in the determined group of small cell base stationsand/or a received response signal, e.g. a received RRC connectionestablishment signal, from the UE in response to a page transmitted bythe macro cell base station, a component 28441 configured to generate apaging response messaging indicating one or paging success or pagingfailure to page the UE, and a component 28442 configured to operate themacro cell base station to send the network node, e.g., the AMF, apaging response message indicating one of success or failure to page theUE. Assembly of components 28442 includes a component 2845 configured tocontrol operation as a function of the determination if the pagingattempt was successful, a component 2846 configured to operate the macrocell base station to send, to the network node, e.g., to the AMF, apaging response message indicating that the paging attempt to page theUE was successful, a component 2847 configured to determine if at leastone of the base stations in the set of base stations determined toattempt to page the UE intended to use unlicensed spectrum for thepaging attempt and to control operation as a function of thedetermination, a component 2848 configured to operate the macro cellbase station to send, e.g., to the network node, e.g. to the AMF, apaging response message indicating that the paging attempt to page theUE failed, and a component 2849 configured to operate the macro basestation to send, e.g., to the network node, e.g., to an AMF, a pagingresponse message indicating that the paging attempt to page the UEfailed, said paging response message indicating the reason or reasonsthat the paging attempt failed, e.g., unavailability of unlicensedspectrum and/or UE did not respond to transmitted paging signals. Thecomponents in assembly of components 2800 may be used to perform themethod steps of FIG. 15A and FIG. 15B as well as the method steps ofFIG. 15C and FIG. 15D.

FIG. 29, comprising the combination of FIG. 29A and FIG. 29B, is adrawing of an exemplary assembly of components 2900, comprising Part A2901 and Part B 2903, which may be included in a small cell base stationin accordance with an exemplary embodiment. For example, assembly ofcomponents 2900 is included in any of the small cell base stations(1608, 1610, 1612, 1614, 1616) of FIG. 16-24, in any of the small cellbase stations (1608′, 1610′, 1612′, 1614′, 1616′) of FIG. 30, in any ofthe small cell base stations (1608″, 1610″, 1612″, 1614″, 1616″) of FIG.31 and/or in a small cell base station implementing the method offlowchart 2500 of FIG. 25 and/or in small cell base station 2700 of FIG.27.

The components in the assembly of components 2900 can, and in someembodiments are, implemented fully in hardware within the processor2702, e.g., as individual circuits. The components in the assembly ofcomponents 2900 can, and in some embodiments are, implemented fully inhardware within the assembly of components 2708, e.g., as individualcircuits corresponding to the different components. In other embodimentssome of the components are implemented, e.g., as circuits, within theprocessor 2702 with other components being implemented, e.g., ascircuits within assembly of components 2708, external to and coupled tothe processor 2702. As should be appreciated the level of integration ofcomponents on the processor and/or with some components being externalto the processor may be one of design choice. Alternatively, rather thanbeing implemented as circuits, all or some of the components may beimplemented in software and stored in the memory 2710 of the small cellbase station 2700, e.g., a gNB or ng-eNB, with the componentscontrolling operation of the base station to implement the functionscorresponding to the components when the components are executed by aprocessor, e.g., processor 2702. In some such embodiments, the assemblyof components 2900 is included in the memory 2710 as assembly ofcomponents 2722. In still other embodiments, various components inassembly of components 2900 are implemented as a combination of hardwareand software, e.g., with another circuit external to the processor 2702providing input to the processor 2702 which then under software controloperates to perform a portion of a component's function. While processor2702 is shown in the FIG. 27 embodiment as a single processor, e.g.,computer, it should be appreciated that the processor 2702 may beimplemented as one or more processors, e.g., computers.

When implemented in software the components include code, which whenexecuted by the processor 2702, configure the processor 2702 toimplement the function corresponding to the component. In embodimentswhere the assembly of components 2900 is stored in the memory 2710, thememory 2710 is a computer program product comprising a computer readablemedium comprising code, e.g., individual code for each component, forcausing at least one computer, e.g., processor 2702, to implement thefunctions to which the components correspond.

Completely hardware based or completely software based components may beused. However, it should be appreciated that any combination of softwareand hardware, e.g., circuit implemented components may be used toimplement the functions. As should be appreciated, the componentsillustrated in FIG. 29 control and/or configure the small cell basestation 2700, or elements therein such as the processor 2702, to performthe functions of corresponding steps illustrated and/or described in themethod of one or more of the flowcharts, signaling diagrams and/ordescribed with respect to any of the Figures. Thus the assembly ofcomponents 2900 includes various components that perform functions ofcorresponding one or more described and/or illustrated steps of anexemplary method, e.g., steps of the method of flowchart 2500 of FIG. 25and/or described or shown with respect to any of the other figures.

Assembly of components 2900 includes a component 2904 configured tooperate the small cell base station to receive, e.g., from a macro cellbase station, a paging request to page a UE, e.g., a first UE, acomponent 2906 configured to determine if the the small cell basestation is using licensed or unlicensed spectrum and to controloperation as a function of the determination, a component 2908configured to operate the small cell base station to perform aListen-Before-Talk (LBT) operation to determine if the unlicensedspectrum is available to use to transmit a paging signal to page the UE,a component 2910 configured to control operation as a function ofwhether or not the unlicensed spectrum is available, a component 2912configured to operate the small cell base station to transmit a pagingsignal directed to the UE, e.g., for a predetermined time intervaland/or for a predetermined number of times, to page the UE, e.g., inresponse to a determination that the unlicensed spectrum is available,and a component 2914 configured to operate the small cell base stationto monitor for a response signal from the UE, e.g., a RRC connectionestablishment signal, in response to the paging signal which wastransmitted by the small cell base station. Component 2914 includes acomponent 2916 configured to operate the small cell base station toreceive a response signal, e.g., a RRC connection establishment signal,from the UE.

Assembly of components 2900 further includes a component 2916 configuredto determine if a criteria for maximum paging transmission attempts hasbeen reached without receiving a response from the UE and to controloperation as a function of the determination, and a component 2924configured to determine if either of: i) the maximum time limit forperforming listen before talk (LBT) checks on unlicensed spectrum forthis paging message, e.g., prior to paging using unlicensed spectrum inaccordance with the timing structure, has been reached, or ii) thepaging message exceeded the allowable time for a paging message to be inthe base station buffer, has been satisfied and to control operation asa function of the determination.

Assembly of components 2900 further includes a component 2920 configuredto decide to include a paging success indicator in a paging responsemessage to be generated, e.g., in response to a received responsesignal, e.g. a RRC connection establishment signal, from the UE, acomponent 2922 configured to decide to include a paging failureindicator, e.g., a fault code indicator indicating failure to respond totransmitted paging signals, in a paging response message to begenerated, e.g., in response to a determination that the criteria formaximum paging transmission attempts has been reached without receivinga response from the UE, a component 2925 configured to decide togenerate a paging failure response message communicating, e.g., eitherexplicitly (with a failure cause code) or implicitly (by the presence ofthe paging failure response message) that the paging attempt by thesmall cell base station to page the UE failed because unlicensedspectrum was unavailable, e.g., in response to the LBT operationsdetermining that the channel is not clearer and the maximum time forperforming LBT having been reached, a component 2596 configured todecide to include a paging failure indicator, e.g., a paging failurefault code indicating that the reason for the failure is that unlicensedspectrum is unavailable and the small cell base station was unable totransmit paging signals to page the UE, in a paging response message tobe generated, and a component 2934 configured to generate a pagingresponse message, said paging response message indicating one of: i) anattempt by the small cell base station to page the UE was successful orii) an attempt by the small cell base station to page the UE wasunsuccessful. Component 2934 includes a component 2936 configured togenerate a paging response message indicating the paging attempt to pagethe UE was successful, a component 2938 configured to generate a pagingresponse signal indicating that the paging attempt to page the UE was afailure and the reason for the failure is that the UE did not respond tothe paging signals transmitted by the small cell base station, and acomponent 2940 configured to generate a paging failure response messagewhich communicates, e.g., explicitly or implicitly, that the pagingattempt by the small cell base station to page the UE failed and thereason for the paging attempt failure is unavailable of unlicensedspectrum resulting in no paging signs to page the UE being transmittedby the small cell base station. In some embodiments, component 2940includes component 2941 configured to generate a paging response signalindicating, e.g., via an included paging failure indicator and/or via anincluded paging fault code indicator, that the paging attempt to pagethe UE was a failure and the reason for the failure is that unlicensedspectrum was unavailable so the small cell base station was unable totransmit the paging signal. Assembly of components 2900 further includesa component 2942 configured to operate the small cell base station tosend the generated paging response signal to the macro cell basestation.

FIG. 30 is a drawing of an exemplary communications system 3000 in whichboth the macro cell base stations and small cell base stations useunlicensed spectrum, in accordance with an exemplary embodiment.Exemplary communications system 3000 is the similar to exemplarycommunications system 1600 of FIG. 16; however, the macro base stations(macro cell base station 1 1604′, macro cell base station 2 1606′) ofexemplary system 3000 of FIG. 30 use unlicensed spectrum correspondingto frequency bands (F1, F2), respectively, replacing the macro basestations (macro cell base station 1 1604, macro cell base station 21604) of system 1600 of FIG. 16 which use licensed spectrum. Inaddition, the small cell base stations (small cell base station 1 1608′,small cell base station 2 1610′, small cell base station 3 1612′, smallcell base station 4 1614′, small cell base station 5 1616′) of exemplarysystem 3000 of FIG. 30, which use unlicensed spectrum corresponding tofrequency band F3, replace the small cell base stations (small cell basestation 1 1608, small cell base station 2 1610, small cell base station3 1612, small cell base station 4 1614, small cell base station 3 1616)of exemplary system 1600 of FIG. 16.

Thus in exemplary system 3000, a macro cell base station (1604′, 1606′)which intends to transmit, via its wireless transmitter, a paging signalto page a UE, also performs a listen-before-talk operation to determineif the unlicensed spectrum that it would use, is currently available;and the macro cell base station may, and sometime does, report that itwas unsuccessful in its attempt to page a UE because it was unable totransmit a paging signal due to the unavailability of unlicensedspectrum. In the exemplary system 3000 of FIG. 30, base stationscorresponding to overlapping coverage areas have been assigned to usedifferent frequency bands of unlicensed spectrum.

In some embodiments, the small cell base stations (small cell BS 11608′, small cell base station 2 1610′) correspond to dead zones in thecoverage area 1605 of macro cell base station 1 1604′. In someembodiments, the small cell base stations (small cell BS 1 1608′, smallcell base station 2 1610′) are used to provide an alternative carrier inthe coverage area 1605 of macro cell base station 1 1604′. In someembodiments, the small cell base stations (small cell BS 4 1614′, smallcell base station 5 1616′) correspond to dead zones in the coverage area1607 of macro cell base station 2 1606′. In some embodiments, the smallcell base stations (small cell BS 4 1614′, small cell base station 51616′) are used to provide an alternative carrier in the coverage area1607 of macro cell base station 2 1606′.

The macro base stations (1604′, 1606′) may be, and sometimes are,implemented in accordance with exemplary macro cell base stations 2600of FIG. 26. The base stations (1604′, 1606′) may, and sometimes do,implement steps of a method in accordance in accordance with flowchart1500 of FIG. 15.

The small base stations (1608′, 1610′, 1612′, 1614′, 1616′) may be, andsometimes are, implemented in accordance with exemplary small cell basestations 2700 of FIG. 27. The small cell base stations (1608′, 1610′,1612′, 1614′, 1616′) may, and sometimes do, implement steps of a methodin accordance in accordance with flowchart 2500 of FIG. 25.

FIG. 31 is a drawing of an exemplary communications system 3100 in whichthe macro cell base stations (macro cell base station 1 1604″, macrocell base station 2 1606″) use licensed spectrum, some of the small cellbase stations (small cell base station 1 1608″, small cell base station5 1616″) use unlicensed spectrum, and some of the small cell basestations (small cell base station 2 1610″, small cell base station 31612″, small cell base station 4 1614″) use licensed spectrum, inaccordance with an exemplary embodiment. Exemplary communications system3100 is the similar to exemplary communications system 1600 of FIG. 16;however, the macro base stations (macro cell base station 1 1604″, macrocell base station 2 1606″) of exemplary system 3100 of FIG. 31 useunlicensed spectrum corresponding to frequency band (F1), replacing themacro base stations (macro cell base station 1 1604, macro cell basestation 2 1604) of system 1600 of FIG. 16 which use licensed spectrum.

In addition, the small cell base stations (small cell base station 11608″ which uses unlicensed spectrum, small cell base station 2 1610″which uses licensed spectrum corresponding to frequency band F3, smallcell base station 3 1612″ which uses licensed spectrum corresponding tofrequency band F2, small cell base station 4 1614″ which uses licensedspectrum corresponding to frequency band F3, small cell base station 51616″ which uses unlicensed spectrum) of exemplary system 3100 of FIG.31, replace the small cell base stations (small cell base station 11608, small cell base station 2 1610, small cell base station 3 1612,small cell base station 4 1614, small cell base station 5 1616) ofexemplary system 1600 of FIG. 16.

The small base stations (1608″, 1610″, 1612″, 1614″, 1616″) may be, andsometimes are, implemented in accordance with exemplary small cell basestations 2700 of FIG. 27. The small cell base stations (1608″, 1610″,′1612″, 1614″, 1616′″) may, and sometimes do, implement a steps of amethod in accordance in accordance with flowchart 2500 of FIG. 25.

In some embodiments, the small cell base stations (small cell BS 11608″, small cell base station 2 1610″) correspond to dead zones in thecoverage area 1605 of macro cell base station 1 1604″. In someembodiments, the small cell base stations (small cell BS 1 1608″, smallcell base station 2 1610″) are used to provide an alternative carrier inthe coverage area 1605 of macro cell base station 1 1604″. In someembodiments, the small cell base stations (small cell BS 4 1614″, smallcell base station 5 1616″) correspond to dead zones in the coverage area1607 of macro cell base station 2 1606″. In some embodiments, the smallcell base stations (small cell BS 4 1614″, small cell base station 51616″) are used to provide an alternative carrier in the coverage area1607 of macro cell base station 2 1606″.

The macro cell base stations (1604″, 1606″) may be, and sometimes are,implemented in accordance with exemplary macro cell base stations 2600of FIG. 26. The base stations (1604″, 1606″) may, and sometimes do,implement steps of a method in accordance in accordance with flowchart1500 of FIG. 15.

The small base stations (1608′, 1616′) may be, and sometimes are,implemented in accordance with exemplary small cell base station 2700 ofFIG. 27. The small cell base stations (1608″, 1616″) may, and sometimesdo, implement steps of a method in accordance in accordance withflowchart 2500 of FIG. 25.

FIG. 32 is a drawing of an exemplary paging response message 3200 inaccordance with some exemplary embodiments, e.g., some embodiments, inwhich both paging success and paging failure response messages aregenerated and transmitted. Exemplary paging response message 3200 is,e.g., a paging response message which communicates a paging successresponse message or a paging failure response message. Exemplary pagingresponse message 3200 is, e.g., generated and sent from a small cellbase station to a macro cell base station, e.g., in response to a pagingrequest message received by the small cell base station which waspreviously sent by the macro cell base station. Exemplary paging requestmessage 3200 includes a paging request message ID value 3202,identifying the previously received paging request message which isbeing responded to, a small cell base station ID 3204 identifying thesmall cell base station which generated the paging response message, aUE device ID 3206 identifying the UE which was requested to be paged, apaging attempt success/fail indicator value 3208, e.g., 1 bitidentifying whether the paging attempt to page the UE was a success(e.g., value=1) or whether the paging attempt to page the UE was afailure (e.g., value=0). If the paging response message 3200 iscommunicating a paging failure response then, paging response message3200 further includes a paging fault code indicator value 3210, e.g., 1bit identifying whether the paging attempt failure was due to the UE notresponding to transmitted paging signals from the UE (e.g., fault codebit=0) or the paging attempt failure was due to unavailability ofunlicensed spectrum (as determined by LBT operation(s)) resulting in thesmall cell base station not transmitting paging signal to page the UE(e.g., fault code bit=1).

FIG. 33 is a drawing of another exemplary paging response message 3300in accordance with some exemplary embodiments, e.g., some embodiments,in which paging failure response messages are generated and transmitted.Exemplary paging response message 3300 is, e.g., a paging responsemessage which communicates a paging failure response message indicatingeither: i) the failure was due to no response from the UE or ii) thefailure was due to unavailability of unlicensed spectrum. Exemplarypaging response message 3300 is, e.g., generated and sent from a smallcell base station to a macro cell base station, e.g., in response to apaging request message received by the small cell base station which waspreviously sent by the macro cell base station. Exemplary paging requestmessage 3300 includes a paging request message ID value 3302,identifying the previously received paging request message which isbeing responded to, a small cell base station ID 3304 identifying thesmall cell base station which generated the paging response message, aUE device ID 3306 identifying the UE which was requested to be paged,and a paging fault code indicator value 3310, e.g., 1 bit identifyingwhether the paging attempt failure was due to the UE not responding totransmitted paging signals from the UE (e.g., fault code bit=0) or thepaging attempt failure was due to unavailability of unlicensed spectrum(as determined by LBT operation(s)) resulting in the small cell basestation not transmitting paging signals to page the UE (e.g., fault codebit=1).

FIG. 34 is a drawing of another exemplary paging response message 3400in accordance with some exemplary embodiments, e.g., some embodiments,in which paging failure response messages are generated and transmitted,in response to a determination of unavailability of unlicensed spectrum.Exemplary paging response message 3400 is, e.g., a paging responsemessage which communicates a paging failure response message implicitlyindicating failure due to unavailability of unlicensed spectrum.Exemplary paging response message 3400 is, e.g., generated and sent froma small cell base station to a macro cell base station, e.g., inresponse to a paging request message received by the small cell basestation which was previously sent by the macro cell base station.Exemplary paging request message 3400 includes a paging request messageID value 3402, identifying the previously received paging requestmessage which is being responded to, a small cell base station ID 3404identifying the small cell base station which generated the pagingresponse message, and a UE device ID 3406 identifying the UE which wasrequested to be paged. In some embodiments, implementing paging responsemessage 3400, the small cell base station does not send a paging successresponse message to the macro cell base station in response to pagingsuccess and does not send a paging failure response message to the macrocell base station in response to paging failure due to the UE notresponding to transmitted paging signals.

Various aspects and/or features of some embodiments are described below.Some embodiments, are directed to a 3GPP NR and/or 3GPP NR-U nodes. Insome such embodiments, there are macro cell base stations and there aresecondary node base stations. In such embodiments, macro cell basestations and small cell base stations are expected to communicate witheach other using Xn signalling as defined in TS 38.420 and relatedspecifications.

Exemplary NR-U operation, in some embodiments, is described below. Insome embodiments, an AMF node instructs a base station node operating inparts or only on unlicensed spectrum to perform a paging operation for agiven UE. In some embodiments, the selected base station node willattempt to (re-) transmit the paging message N number of times and/orduring a T duration. If the Paging message wasn't sent due to LBT notclearing for unlicensed carriers, involved base station will generateand send a novel N2-AP:PAGING_U RESPONSE msg to the AMF indicatingappropriate cause code (e.g. Message not sent due to non-availability ofunlicensed channels.)

Exemplary NR-U operation, in some embodiments, is described below. Insome embodiments, if a macro cell base stations is allowed to instruct asmall cell base station to page in addition to itself, then it does so.Therefore, macro cell base station and any selected small cell basestations (by macro cell base station) will start paging the identifiedUE(s). This could include paging operations over licensed and/orunlicensed carriers. In some embodiments, each selected small cell basestation node will attempt to re-transmit the page message N number oftimes and/or during a T duration. If the Paging message wasn't sent dueto LBT not clearing for unlicensed carriers, involved small cell basestations will send a novel Xn-AP:PAGING_U RESPONSE message to MN overXn. Once the macro cell base station has received the Xn-AP:PAGING_URESPONSE msg(s) from some or all of the selected small cell basestations, macro cell base station decides to send, generates and sends aN2-AP:PAGING_U RESPONSE msg to AMF indicating appropriate cause code(Message not sent due to non-availability of unlicensed channels.)

The criteria for how macro cell base station selects small cell basestations to instruct to page is depends on the particular embodiment.Step 1508 of flowchart 1500 of FIG. 15 describes exemplary selectionincluding a plurality of different types of information and/or factors,e.g., historical cell information, UE mobility pattern information,measurement reports, channel quality feedback information for potentialcarrier aggregation (CA) targets, PDDCH channel load on macro cell dueto paging, reported signal strength of macro cell base station signal,number of UEs requiring paging, number of small cell base stationsunder, e.g., with potentially varying amounts of overlap, a macro cellbase station's coverage area, radio network planning data, UE reports,etc., upon which the selection may be, and sometimes is, based. Invarious embodiments, at different times, and/or for different UEs,different sets of one or more of the plurality of different types ofinformation and/or factors described above are used to make theselection of the set of base stations which are to attempt a page. Insome embodiments, the selection can be, and sometimes is, based on: a)an indicator communicated from the network node, e.g., AMF, to the macrocell base station, as to whether paging via small cell base stations isallowed and b) radio network planning data.

In some embodiments, unlicensed spectrum cells are used to fill licensedcarrier coverage gaps. In an exemplary embodiment, there are two macrocell base stations (macro cell base station 1 (G1) using licensedfrequency FR1 and macro cell base station 2 (G2) using licensedfrequency FR2) and 3 small cell base stations (small cell base station 1(S1), small cell base station 2 (S2), small cell base station 3 (S3).Small cells operating in unlicensed carriers are deployed to fillcoverage holes left by macro nodes (gNB/ng-eNB). This is expected to becommon for “indoor hot-spot” type coverage where outdoor signal suffershigh attenuation, and is therefore augmented by deploying small cells atstrategic locations to offset the outdoor to indoor (O2I) penetrationloss. This approach applies also to cases of when centralunit-distributed unit (CU-DU) and/or central unit—control plane/userplance (CU-CP/UP) split is employed.

Continuing with the exemplary scenario, macro cell 1's (G1's) coveragearea fully covers small cell 1's (S1's) and small cell 2's (S2's)coverage area, and partially covers small cell 3's (S3's) coverage area.Macro cell 2's coverage is non-overlapping with macro cell 1's coverage.Macro cell 2's coverage area partially covers small cell 3's coveragearea. In some embodiments, there are other macro and small cell nodeswith full or partial coverage overlaps.

With respect to outdoor-to-indoor signal penetration, consider that:

For 3.5 GHz, O2I penetration loss for concrete blocks is around 20-23dB, poured concrete (w/o hollow cavities) is around 40-45 db, and acomplete signal attenuation for modern-day low-E glass (e.g. the kindmandated for state of Colorado).

For 28 GHz, O2I penetration loss is around 25-28 dB for high-E glass,and complete signal attenuation for concrete (hollow or otherwise), andmodern-day low-E glass.

Given the penetration loss range, depending on the building type (e.g.double-walled residential, high-E glass, low-E glass, concrete etc) andfrequency used, for a subscriber who is situated indoors, the outdoorsignal (from the macro node G1) is unlikely to penetrate indoor. In suchscenarios, UE may be out of coverage of macro node (G1 and G2) but incoverage of (either outdoor or indoor) small cells (S3 gNB). If the UEunderwent RRC_CONNECTED→RRC_IDLE/INACTIVE transition in the small cell(as the best cell for this UE), then subsequent pages can be routed vialast_known_NGCI (which will point to this small cell). However, if UEunderwent RRC_CONNECTED→RRC_IDLE/INACTIVE transition under the macrocell, and subsequently moved indoors under the small cell coverage,initial paging via macro node (G1) will fail. At this point, a pagingarea escalation will occur wherein multiple macro nodes in TATA_list(spanning G1, G2 etc) will be paged. This may not include small cell(s)or if it does then the number of small cell(s) which get included couldbe rather large. For example, for every Macro cell in lower FR1 range,there's likely to be a minimum of 3-10 small cells. In some embodiments,a given small cell could be under the coverage area of no more than 2-3macro cells. Depending on the multiple factors, the number of cellsunder a Tracking area (TA) can range from 500-6000 spanning 30-300+ basestations. This causes an increased PDCCH load with a possible net effectof being unable to reach subscriber anyways. Thus the addition of manysmall cell base stations may be expected to cause problems with regardto PDCCH load.

In accordance with a novel feature of some embodiments, such scenariosand potential problems are tackled by letting NG-RANs (macro cell basestations which are gNBs or ng-eNBs) decide when and how to include thesmall cells (under a macro cell area) for paging operations. In someembodiments, the notion of “Cell grouping for a given UE when inIDLE/INACTIVE mode” is used. Via implementation specific means e.g.normal radio network planning data fed via OAM, ANR, SON etc. anoperator can, and sometimes does, provision in Macro nodes (macro cellbase stations) with a list of possible small cell nodes (small cell basestations) under its hierarchy. The small cells would generally beexpected to either fall under or augment the macro node's coverage area.In some embodiments, the macro nodes (macro cell base stations) areconsidered and referred to as master nodes and the small cell basestations are referred to as secondary nodes.

In some embodiments, For RRC_IDLE mode or RRC_INACTIVE UEs, the “Cellgrouping for a given UE when in IDLE/INACTIVE mode” list can be, andsometimes is, taken from either the provisioned/learned associations orfrom the last known cell(s) from which the UEs last underwent thetransition.

In some embodiments, depending on multiple factors such as PDCCH channelloading due to paging etc, when paged by core node CN (e.g., AMF), amacro node could, and sometimes does, request such (fixed association)neighbor secondary nodes (which could operate in unlicensed spectrum) toalso page the UE. The secondary nodes are, e.g., small cell basestations using unlicensed spectrum.

Correspondingly, in some embodiments, a mechanism in NG-RAN (macro basestations) is also implemented to allow NG-RAN to control whether andwhen NG-AP:PAGING message is sent over macro cells only or small cellsonly or simultaneously in both.

In some embodiments, “Cell grouping for a given UE while inIDLE/INACTIVE mode” is intended to apply on a per-UE basis. In someembodiments, for the same UE, the cell grouping can be changed (by macrocell) at any RRC_IDLE or RRC_INACTIVE transition from RRC_CONNECTEDmode. In some embodiments, the “Cell grouping for a given UE while inIDLE/INACTIVE mode” is intended to apply to a group of UEs under thesame small cell coverage under the same macro cell coverage.

In some embodiments, the master cell (macro cell base station) can, andsometimes does, generate the required cell grouping for a given UE(e.g., Cell grouping for a given UE while in IDLE/INACTIVE mode) usingimplementation means including but not limited to normal radio networkplanning data fed via OAM, updated via ANR and/or SON.

In some embodiments, the macro cell can, and sometimes does, generatethe required cell grouping for a given UE (e.g., Cell grouping for agiven UE while in IDLE/INACTIVE mode) from either the historical cellinformation submitted by UE to master cell during RRC ConnectionEstablishment or RRC Connection Release or from hysteresis maintained bymaster cell based on UE's mobility patterns.

In addition, in some embodiments, if both the network and UE supportenhancements related to LTE_euCA feature (3GPP Rel-14 and Rel-15), thenthe macro cell will have both the measurement reports along with CQIfeedback for potential CA target SCells, and that information can be,and sometimes is, used to determine the cell grouping for a given UE.

Various described features and/or aspects of the current inventionincluding, e.g. macro cell base station/small cell base station paginginteractions, and cell grouping for a given UE with regard to paging,are applicable in licensed spectrum only embodiments, a embodimentincluding a mix of licensed and unlicensed spectrum, or unlicensedspectrum only embodiments.

In some embodiments, the macro cell base station can, and does,determine whether, when and which small cells to include for for theadditional paging operations based on a number of criteria, including,but not limited to, one or more or all of:

-   -   PDCCH channel load on macro cell due to paging operations,    -   Last known or average strength (e.g. RSRQ) of macro cell as        reported by the    -   UE (indicative of how strong or weak of a signal the UE is        experiencing from the macro cell),    -   Number of UEs requiring paging,    -   Number of small cells under the macro cell's coverage.    -   Information at macro node's disposal, or    -   Information UE reports.

In some embodiments, a Radio Resource Control (RRC) command is used by abase station to release the RRC connection between the base station anda specific UE.

The RRC Release message is used to command the release of an RRCconnection or the suspension of the RRC connection.

In some exemplary embodiments, a novel RRC Release message, includes oneor more of the following:

A new IE termed as “PagingPriorityListNR” referring to NR “Cell groupingfor a given UE while in IDLE/INACTIVE mode” for which the UE monitorspaging information in addition to serving cell from where it receivedthis IE. The list of grouped cells may be an ordered list in descendingpriority. In some cases a new (information element) IE termed as“cellsPerDRXToMonitor” to indicate the subset of such an ordered list ofcells the UE is expected to scan is included in the RRC Release message.

A new IE termed as “PagingPriorityListEUTRA” referring to EUTRA “Cellgrouping for a given UE while in IDLE/INACTIVE mode” for which the UEmonitors paging information in addition to serving cell from where itreceived this IE.

Type-2 PDCCH search space information for each grouped cell in which theUE monitors paging messages, i.e., it looks for DCI Formats scrambledwith P-RNTI. If a UE is not provided higher layer parameter pagingSearchSpace for Type2-PDCCH common search space set, the Type2-PDCCHcommon search space set is assumed to be the same as the Type0-PDCCHcommon search space set. Further considerations of the PDCCH searchspace monitoring are as follows. Monitoring paging on multiple cells canbe an energy-intensive procedure for the UE, especially due to theimpact on UE DRX if it has to keep waking up to monitor different pagingoccasions (POs) on different cells. In order to improve UE energyefficiency, the following solutions are implemented in some but notnecessarily all embodiments:

Assuming the UE DRX cycle is synchronized across some or all of thegrouped cells, in each DRX ON duration the UE monitors paging on one ormore pre-determined cells, as opposed to all cells. Therefore, overmultiple ON durations the UE will cycle through all the cells. Thepre-determined ordering may be indicated in the RRC Release message via“cellsPerDRXToMonitor” IE.

To reduce PDCCH monitoring and blind detection impacts, the pagingoccasions on multiple cells for a given UE may be grouped in time suchthat the UE does not need to monitor more than X consecutive slots at atime in order to scan POs on all the configured group cells.Furthermore, the POs may, and sometimes do have sufficient gaps in time(for e.g., somewhere in the range of two-four OFDM symbols) in order toallow the UE sufficient time to switch bandwidth parts (BWPs) whencycling from one cell to the next.

In some but not necessarily all embodiments, the novel RRC Releasemessage includes:

A maximum number of grouped secondary cells which UE monitors for paginginformation.

A maximum duration for which UE monitors paging information in groupedsecondary cells. Upon expiration of this duration, the UE stopsmonitoring for paging information in grouped secondary cells.

In some embodiments, for a list of carriers, e.g. a list of carriersdenoted by PagingPriorityListNR IEs and PagingPriorityListEUTRA IEsreceived by the UE in RRCRelease message, the UE listens for paginginformation, in accordance with its idle mode DRX values, for saidcarriers.

In the following sets of embodiments the number of an embodiment refersto the numbered embodiment in the same set.

Second Numbered List of Exemplary Method Embodiments

Method Embodiment 1 A communications method, the method comprising:receiving (1504), at a first base station, a paging request to page afirst UE device; determining (1506), at the first base station, a firstset of base stations which are to attempt to page the first UE device,said first set of base stations including a small cell base station;sending (1532), from the first base station, a paging request message tothe small cell base station in said first set of base stations, saidpaging request message requesting paging of the first UE device; andreceiving (1542), at the first base station, a paging response messagefrom the small cell base station, said paging response messageindicating one of: i) an attempt at the small cell base station to pagethe first UE device was successful or ii) an attempt at the small cellbase station to page the first UE device was unsuccessful.

Method Embodiment 2 The communications method of Method Embodiment 1,wherein the first base station is a macro base station; and wherein saidsmall cell base station is a first small cell base station having acoverage area smaller than the coverage area of said macro base station.

Method Embodiment 3 The method of Method Embodiment 2, wherein the firstbase station uses licensed spectrum; and wherein the first small cellbase station uses unlicensed spectrum.

Method Embodiment 4 The method of Method Embodiment 3, wherein the firstsmall cell base station is within the coverage area of the first basestation and fills in a dead zone in the first base station coveragearea.

Method Embodiment 5 The method of Method Embodiment 2, wherein the firstbase station and said first small cell base station both use unlicensedspectrum but the first base station and the first small cell basestation use different frequency bands.

Method Embodiment 6 The method of Method Embodiment 2, wherein the firstsmall cell base station is within the coverage area of the first basestation and fills in a dead zone in the first base station coveragearea.

Method Embodiment 7 The method of Method Embodiment 2, wherein the firstsmall cell base station has a coverage area which partially overlaps thefirst (macro) base station coverage area and the coverage area ofanother (macro cell) base station, said first small cell base stationbeing at a location corresponding to a boundary area between macro cellbase stations.

Method Embodiment 8 The method of Method Embodiment 2, whereindetermining (1506), at the first base station, the first set of basestations which are to attempt to page the first UE device includesdetermining the first set of base stations based on one or more of: i)historical cell information (1510); ii) first UE mobility patterninformation (1512); iii) signal measurement reports communicated by thefirst UE to the first base station (1514); iv) channel qualityinformation feedback (1516) communicated by the first UE to the firstbase station or another network device, v) physical downlink controlchannel load on a physical downlink control channel (PDCCH) at the firstbase station (1518), vi) a received signal strength (1520) (e.g., lastknown or average received signal strength) of a signal (e.g., RSRQsignal) transmitted by the first base station as reported to the firstbase station to by the first UE, vii) number (1522) of UEs requiringpaging, vii) a number (1524) of small cells under a coverage area of thefirst base station, viii) radio network planning data (1526) or ix)received UE reports (1530).

Method Embodiment 9 The method of Method Embodiment 8, wherein saiddetermining the first set is based on at least two of: i) historicalcell information (1510); ii) first UE mobility pattern information(1512); iii) signal measurement reports communicated by the first UE tothe first base station (1514); iv) channel quality information feedback(1516) communicated by the first UE to the first base station or anothernetwork device, v) physical downlink control channel load on a physicaldownlink control channel (PDCCH) at the first base station (1518), vi) areceived signal strength (1520) (e.g., last known or average receivedsignal strength) of a signal (e.g., RSRQ signal) transmitted by thefirst base station as reported to the first base station to by the firstUE, vii) number (1522) of UEs requiring paging, vii) a number (1524) ofsmall cells under a coverage area of the first base station, viii) radionetwork planning data (1526) and ix) received UE reports (1530).

Method Embodiment 10 The method of Method Embodiment 9, wherein saiddetermining the first set of base stations is based on at least threeof: i) historical cell information (1510); ii) first UE mobility patterninformation (1512); iii) signal measurement reports communicated by thefirst UE to the first base station (1514); iv) channel qualityinformation feedback (1516) communicated by the first UE to the firstbase station or another network device (1518), v) physical downlinkcontrol channel load on a physical downlink control channel (PDCCH) atthe first base station, vi) a received signal strength (1520) (e.g.,last known or average received signal strength) of a signal (e.g., RSRQsignal) transmitted by the first base station as reported to the firstbase station to by the first UE, vii) number (1522) of UEs requiringpaging, vii) a number (1524) of small cells under a coverage area of thefirst base station, viii) radio network planning data (1526) and ix)received UE reports (1530).

Method Embodiment 11 The method of Method Embodiment 2, wherein thepaging response message from the first small cell base station indicatesa paging failure (1543) and wherein the paging response message from thefirst small cell base station further indicates the reason for thepaging attempt failure.

Method Embodiment 12 The method of Method Embodiment 11, wherein thepaging response message includes information (e.g., a failure causecode) indicating the reason for the paging attempt failure whichindicates one of: i) unavailability of the unlicensed spectrum (LBTfails to clear) resulting in no paging signal transmitted by the firstsmall cell base station or ii) no response received from the first UEdevice in response to a transmitted paging signal.

Method Embodiment 13 The method of Method Embodiment 2, wherein thepaging response message from the first small cell base station indicatesa paging failure (1543) and indicates (explicitly (e.g., via a fail codeincluded in the message) or implicitly (e.g., via transmission of thepaging response message) the reason for the paging attempt failure isunavailability of the unlicensed spectrum (LBT fails to clear) resultingin no paging signal being transmitted by the first small cell basestation.

Method Embodiment 14 The method of Method Embodiment 2, wherein saidpaging request to page a first UE device received at the first basestation is received from a network device (e.g., Access and mobilitymanagement Function (AMF)); and wherein the method further comprises:sending (15441), from the first base station, a paging results message(e.g., paging response message) to the network device (e.g., the AMF),said paging results message indicating one of success or failure to pagethe first UE.

Method Embodiment 15 The communications method of Method Embodiment 1further comprising: receiving (1504), at a first base station, anadditional paging request to page the first UE device; determining(1506), at the first base station, an additional set of base stationswhich are to attempt to page the first UE device, said additional set ofbase stations including an additional small cell base station which isnot included in said first set of base stations (at second time at leastone different small cell is selected); sending (1532), from the firstbase station, a paging request message to the additional small cell basestation in said second set of base stations, said paging request messageto the additional small cell requesting paging of the first UE device;and receiving (1542), at the first base station, a paging responsemessage from the additional small cell base station, said pagingresponse message indicating one of: i) an attempt at the additionalsmall cell base station to page the first UE device was successful orii) an attempt at the additional small cell base station to page thefirst UE device was unsuccessful.

Method Embodiment 16 The method of Method Embodiment 1, furthercomprising: receiving (1554), at a first base station, a second pagingrequest, said second paging request being a request to page a second UEdevice; determining (1556), at the first base station, a second set ofbase stations which are to attempt to page the second UE device, saidsecond set of base stations including a second small cell base station,said second small cell base station not being in said first set of basestations (second set of base stations is different by at least one smallcell base station with the sets of base stations being selected on a perUE basis using information corresponding to the particular UE, e.g.,with the selection process thus being different for at least somedifferent UEs because of the difference in information corresponding tothe individual UEs which is used to selected the set of base stations toattempt a page); sending (1582), from the first base station, a pagingrequest message to the second small cell base station in said second setof base stations, said paging request message requesting paging of thesecond UE device; and receiving (1592), at the first base station, apaging response message from the second small cell base station, saidpaging response message one of: i) an attempt at the second small cellbase station to page the second UE device was successful or ii) anattempt at the small cell base station to page the second UE device wasunsuccessful.

Method Embodiment 17 The method of Method Embodiment 16, whereindetermining (1556), at the first base station, the second set of basestations which are to attempt to page the second UE device includesdetermining the second set of base stations based on one or more of: i)historical cell information (1560) corresponding to the second UE; ii)second UE mobility pattern information (1562); iii) signal measurementreports (1564) communicated by the second UE to the first base station;iv) channel quality information feedback (1566) communicated by thesecond UE to the first base station or another network device, v)physical downlink control channel (PDDCH) load on a physical downlinkcontrol channel at the first base station (1568), vi) a received signalstrength (1570) (e.g., last known or average received signal strength)of a signal (e.g., RSRQ signal) transmitted by the first base station asreported to the first base station to by the second UE, vii) the number(1572) of UEs requiring paging, vii) the number (1574) of small cellsunder a coverage area of the first base station, viii) radio networkplanning data (1576) or ix) received UE reports (1580).

Method Embodiment 18 The method of Method Embodiment 2, furthercomprising: receiving (2504), at the first small cell base station, thesaid paging request message, sent by the macro base station, requestingpaging of the first UE device; and performing (2508), at the first smallcell base station, in response to said received paging request message,a listen before talk (LBT) operation to determine if unlicensed spectrumis available to use to transmit a paging signal to the first UE device.

Method Embodiment 19 The method of Method Embodiment 18, furthercomprising: generating (2534), at the first small cell base station,said paging response message indicating one of: i) an attempt at thefirst small cell base station to page the first UE device was successfulor ii) an attempt at the first small cell base station to page the firstUE device was unsuccessful; and transmitting (2542), at the first smallcell base station, the generated paging response message to the macrobase station.

Method Embodiment 20 The method of Method Embodiment 19, wherein saidlisten before talk operation determines that the unlicensed spectrum isavailable; and wherein the method further comprises: transmitting(2512), at the first small cell base station, a paging signal from thefirst small cell base station directed to the first UE device;monitoring (2514), at the first small cell base station, for a responseto the paging signal transmitted from the first small cell base station;and deciding (2520), at the first small cell base station, when said themonitoring detected a response (e.g., a RRC connection establishingsignal in response to the transmitted paging signal), to include apaging success indication in the paging response message when generatingthe paging response message; and deciding (2522), at the first smallcell base station, when said the monitoring failed to detect a response,to include a paging failure indication in the paging response messagewhen generating the paging response message.

Method Embodiment 21 The method of Method Embodiment 19, wherein saidlisten before talk operation determines that the unlicensed spectrum isavailable; and wherein the method further comprises: transmitting(2512), at the first small cell base station, a paging signal from thefirst small cell base station directed to the first UE device;monitoring (2514), at the first small cell base station, for a responseto the paging signal transmitted from the first small cell base station;and deciding (2522), at the first small cell base station, when said themonitoring failed to detect a paging response, to include a pagingfailure indication in the paging response message when generating thepaging response message.

Method Embodiment 22 The method of Method Embodiment 21, wherein thepaging response message indicates that the reason for the paging failurewas no response received from the first UE device in response to atransmitted paging signal.

Method Embodiment 23 The method of Method Embodiment 19, wherein saidlisten before talk operation determines that the unlicensed spectrum isunavailable; and wherein the method further comprises: operating (2524)the first small cell base station to determine if either of: i) themaximum time limit for performing listen before talk (LBT) checks on theunlicensed spectrum for this paging message has been reached, or ii) thepaging message exceeded the allowable time for a paging message to be inthe base station buffer, has been satisfied; and wherein said step ofgenerating (2534), at the first small cell base station, said pagingresponse message includes: including (2541) in the paging responsemessage an indication that the paging attempt to page the UE was afailure and that the reason for the failure was that unlicensed spectrumwas unavailable, at the first small cell base station, for transmissionof a paging signal to the first UE.

Method Embodiment 24 The method of Method Embodiment 19, wherein saidlisten before talk operation determines that the unlicensed spectrum isunavailable; and wherein the method further comprises: operating (2524)the first small cell base station to determine if either of: i) themaximum time limit for performing listen before talk (LBT) checks on theunlicensed spectrum for this paging message has been reached, or ii) thepaging message exceeded the allowable time for a paging message to be inthe base station buffer, has been satisfied; and wherein said step ofgenerating (2534), at the first small cell base station, said pagingresponse message includes: generating (2540) a paging failure responsemessage which communicates (either explicitly, e.g., via a failure code,or implicitly, e.g., via the presence of the failure response message)that the paging attempt by the first small cell base station to page thefirst UE failed and the reason for the paging attempt failure isunavailability of the unlicensed spectrum (LBT fails to clear) resultingin no paging signal to page the first UE being transmitted by the firstsmall cell base station.

Numbered List of Exemplary System Embodiments

System Embodiment 1 A communications system (1600 or 3000 or 3100)comprising: a first base station (1604 or 1604′ or 1604″ or 2600)including: a first processor (2602) configured to: operate the firstbase station to receive (1504) (e.g., via a network receiver (2616)) apaging request to page a first UE device (1634); determine (1506) afirst set of base stations which are to attempt to page the first UEdevice, said first set of base stations including a small cell basestation (1608 or 1610 or 1612 or 1608′ or 1610′ or 1612′ or 1608″ or1610″ or 1612″); operate the first base station to send (1532) (e.g.,via a network transmitter (2618)) a paging request message to the smallcell base station in said first set of base stations, said pagingrequest message requesting paging of the first UE device; and operatethe first base station to receive (1542) (e.g., via a networktransmitter) a paging response message from the small cell base station,said paging response message indicating one of: i) an attempt at thesmall cell base station to page the first UE device was successful orii) an attempt at the small cell base station to page the first UEdevice was unsuccessful.

System Embodiment 2 The communications system (1600 or 3000 or 3100) ofSystem Embodiment 1, wherein the first base station (1604 or 1604′ or1604″) is a macro base station; and wherein said small cell base station(1608 or 1610 or 1612 or 1608′ or 1610′ or 1612′ or 1608″ or 1610″ or1612″) is a first small cell base station having a coverage area smallerthan the coverage area of said macro base station.

System Embodiment 3 The communications system (1600 or 3100) of SystemEmbodiment 2, wherein the first base station (1604 or 1604″) useslicensed spectrum; and wherein the first small cell base station (1608or 1610 or 1612 or 1608″) uses unlicensed spectrum.

System Embodiment 4 The communications system (1600 or 3100) of SystemEmbodiment 3, wherein the first small cell base station (1608 or 1610 or1608″) is within the coverage area (1605 or 1605″) of the first basestation (1604 or 1604″) and fills in a dead zone in the first basestation coverage area.

System Embodiment 5 The communications system (3000) of SystemEmbodiment 2, wherein the first base station (1604′) and said firstsmall cell base station (1608′ or 1610′ or 1612′) both use unlicensedspectrum but the first base station and the first small cell basestation use different frequency bands.

System Embodiment 6 The communications system (1600 or 3000 or 3100) ofSystem Embodiment 2, wherein the first small cell base station (1608 or1610 or 1608′ or 1610′ or 1608″) is within the coverage area (1605 or1605′ or 1605″) of the first base station (1604 or 1604′ or 1604″) andfills in a dead zone in the first base station coverage area (1605 or1605′ or 1605″).

System Embodiment 7 The communications system (1600 or 3000 or 3100) ofSystem Embodiment 2, wherein the first small cell base station (1612 or1612′) has a coverage area (1613 or 1613′) which partially overlaps thefirst (macro) base station coverage area (1605 or 1605′) and thecoverage area (1607 or 1607′) of another (macro cell) base station (1606or 1606′), said first small cell base station being at a locationcorresponding to a boundary area between macro cell base stations.

System Embodiment 8 The communications system (1600 or 3000 or 3100) ofSystem Embodiment 2, wherein said first processor (2602) is configuredto: determine the first set of base stations based on one or more of: i)historical cell information (1510); ii) first UE mobility patterninformation (1512); iii) signal measurement reports communicated by thefirst UE to the first base station (1514); iv) channel qualityinformation feedback (1516) communicated by the first UE to the firstbase station or another network device, v) physical downlink controlchannel load on a physical downlink control channel (PDCCH) at the firstbase station (1518), vi) a received signal strength (1520) (e.g., lastknown or average received signal strength) of a signal (e.g., RSRQsignal) transmitted by the first base station as reported to the firstbase station to by the first UE, vii) number (1522) of UEs requiringpaging, vii) a number (1524) of small cells under a coverage area of thefirst base station, viii) radio network planning data (1526) or ix)received UE reports (1530), as part of being configured to determine(1506) the first set of base stations which are to attempt to page thefirst UE device.

System Embodiment 9 The communications system (1600 or 3000 or 3100) ofSystem Embodiment 8, wherein said determining the first set is based onat least two of: i) historical cell information (1510); ii) first UEmobility pattern information (1512); iii) signal measurement reportscommunicated by the first UE to the first base station (1514); iv)channel quality information feedback (1516) communicated by the first UEto the first base station or another network device, v) physicaldownlink control channel load on a physical downlink control channel(PDCCH) at the first base station (1518), vi) a received signal strength(1520) (e.g., last known or average received signal strength) of asignal (e.g., RSRQ signal) transmitted by the first base station asreported to the first base station to by the first UE, vii) number(1522) of UEs requiring paging, vii) a number (1524) of small cellsunder a coverage area of the first base station, viii) radio networkplanning data (1526) and ix) received UE reports (1530).

System Embodiment 10 The communications system (1600 or 3000 or 3100) ofSystem Embodiment 9, wherein said determining the first set of basestations is based on at least three of: i) historical cell information(1510); ii) first UE mobility pattern information (1512); iii) signalmeasurement reports communicated by the first UE to the first basestation (1514); iv) channel quality information feedback (1516)communicated by the first UE to the first base station or anothernetwork device, v) physical downlink control channel load on a physicaldownlink control channel (PDCCH) at the first base station (1518), vi) areceived signal strength (1520) (e.g., last known or average receivedsignal strength) of a signal (e.g., RSRQ signal) transmitted by thefirst base station as reported to the first base station to by the firstUE, vii) number (1522) of UEs requiring paging, vii) a number (1524) ofsmall cells under a coverage area of the first base station, viii) radionetwork planning data (1526) and ix) received UE reports (1530).

System Embodiment 11 The communications system (1600 or 3000 or 3100) ofSystem Embodiment 2, wherein the paging response message from the firstsmall cell base station indicates a paging failure (1543) and whereinthe paging response message from the first small cell base stationfurther indicates the reason for the paging attempt failure.

System Embodiment 12 The communications system of System Embodiment 11,wherein the paging response message includes information (e.g., afailure cause code) indicating the reason for the paging attempt failurewhich indicates one of: i) unavailability of the unlicensed spectrum(LBT fails to clear) resulting in no paging signal transmitted by thefirst small cell base station or ii) no response received from the firstUE device in response to a transmitted paging signal.

System Embodiment 13 The communications system of System Embodiment 2,wherein the paging response message from the first small cell basestation indicates a paging failure (1543) and indicates (explicitly(e.g., via a fail code included in the message) or implicitly (e.g., viatransmission of the paging response message) the reason for the pagingattempt failure is unavailability of the unlicensed spectrum (LBT failsto clear) resulting in no paging signal being transmitted by the firstsmall cell base station.

System Embodiment 14 The communications system (1600 or 3000 or 3100) ofSystem Embodiment 2, wherein said paging request to page a first UEdevice (1634 or 1634′ or 1634″) received at the first base station(1604) is received from a network device (e.g., Access and mobilitymanagement Function (AMF))(1602); and wherein said first processor(2602) is further configured to: operate the first base station (1604)to send (15441) (e.g., via the network transmitter (2618)) a pagingresults message (e.g., paging response message) to the network device(e.g., the AMF), said paging results message indicating one of successor failure to page the first UE.

System Embodiment 15 The communications system (1600) of SystemEmbodiment 1, wherein said first processor (2602) is further configuredto: operate the first base station (1604) to receive (1504), (e.g., viathe network interface) an additional paging request to page the first UEdevice (1634); determine (1506) an additional set of base stations whichare to attempt to page the first UE device, said additional set of basestations including an additional small cell base station (1608) which isnot included in said first set of base stations (at second time at leastone different small cell is selected); operate the first base station(1604 or 1604′ or 1604″) to send (1532) (e.g., via the networktransmitter (2618)) a paging request message to the additional smallcell base station (1608) in said second set of base stations, saidpaging request message to the additional small cell requesting paging ofthe first UE device; and operate the first base station (1604 or 1604′or 1604″) to receive (1542) (e.g., via the network receiver (2616)) apaging response message from the additional small cell base station(1608), said paging response message indicating one of: i) an attempt atthe additional small cell base station to page the first UE device wassuccessful or ii) an attempt at the additional small cell base stationto page the first UE device was unsuccessful.

System Embodiment 16 The communications system (1600 or 3000 or 3100) ofSystem Embodiment 1, wherein said first processor (2602) is furtherconfigured to: operate the first base station (1604 or 1604′ or 1604″)to receive (1554) a second paging request, said second paging requestbeing a request to page a second UE device (1636); determine (1556) asecond set of base stations which are to attempt to page the second UEdevice, said second set of base stations including a second small cellbase station, said second small cell base station not being in saidfirst set of base stations (second set of base stations is different byat least one small cell base station with the sets of base stationsbeing selected on a per UE basis using information corresponding to theparticular UE, e.g., with the selection process thus being different forat least some different UEs because of the difference in informationcorresponding to the individual UEs which is used to selected the set ofbase stations to attempt a page); operate the first base station (1604or 1604′ or 1604″) to send (1582) (e.g., via network transmitter (2618))a paging request message to the second small cell base station in saidsecond set of base stations, said paging request message requestingpaging of the second UE device (1636); and operate the first basestation (1604) to receive (1592) (via the network receiver (2616)) apaging response message from the second small cell base station, saidpaging response message indicating one of: i) an attempt at the secondsmall cell base station to page the second UE device was successful orii) an attempt at the small cell base station to page the second UEdevice was unsuccessful.

System Embodiment 17 The communications system (1600) of SystemEmbodiment 16, wherein said first processor (1602) is configured to:determine the second set of base stations based on one or more of: i)historical cell information (1560) corresponding to the second UE; ii)second UE mobility pattern information (1562); iii) signal measurementreports (1564) communicated by the second UE to the first base station;iv) channel quality information feedback (1566) communicated by thesecond UE to the first base station or another network device (1568), v)physical downlink control channel (PDDCH) load on a physical downlinkcontrol channel at the first base station, vi) a received signalstrength (1570) (e.g., last known or average received signal strength)of a signal (e.g., RSRQ signal) transmitted by the first base station asreported to the first base station to by the second UE, vii) the number(1572) of UEs requiring paging, vii) the number (1574) of small cellsunder a coverage area of the first base station, viii) radio networkplanning data (1576) or ix) received UE reports (1580), as part of beingconfigured to determine (1556) the second set of base stations which areto attempt to page the second UE device.

System Embodiment 18 The communications system (1600) of SystemEmbodiment 2, further comprising: said first small cell base station(1608), said first small cell base station (1608) including: a secondprocessor (2702) configured to: operate the first small cell basestation (1608) to receive (2504) (e.g., via receiver 2716) the saidpaging request message, sent by the macro cell base station (1604),requesting paging of the first UE device (1634); and perform (2508), inresponse to said received paging request message, a listen before talk(LBT) operation to determine if unlicensed spectrum is available to useto transmit a paging signal to the first UE device (1634).

System Embodiment 19 The communications system (1600) of SystemEmbodiment 18, wherein said second processor (2702) is furtherconfigured to: generate (2534) said paging response message indicatingone of: i) an attempt at the first small cell base station (1608) topage the first UE device (1634) was successful or ii) an attempt at thefirst small cell base station (1608) to page the first UE device (1634)was unsuccessful; and operate the first small cell base station (1608)to transmit (2542) (e.g. via transmitter (2718)) the generated pagingresponse message to the macro cell base station (1604).

System Embodiment 20 The communications system (1600) of SystemEmbodiment 19, wherein said listen before talk operation determines thatthe unlicensed spectrum is available; and wherein the second processor(2702) is further configured to: operate the first small cell basestation (2512) to transmit (2510) (e.g., via wireless transmitter(2714)) a paging signal from the first small cell base station (1608)directed to the first UE device (1634); operate the first small cellbase station (1608) to monitor (2514) for a response to the pagingsignal transmitted form the first small cell base station (1608); anddecide (2520), when said the monitoring detected a response (e.g., a RRCconnection establishing signal in response to the transmitted pagingsignal), to include a paging success indication in the paging responsemessage when generating the paging response message; and decide (2522),when said the monitoring failed to detect a response, to include apaging failure indication in the paging response message when generatingthe paging response message.

System Embodiment 21 The communications system (1600) of SystemEmbodiment 19, wherein said listen before talk operation determines thatthe unlicensed spectrum is available; and wherein said second processoris further configured to: operate (2512) the first small cell basestation (1608) to transmit (e.g., via wireless transmitter 2714) apaging signal from the first small cell base station directed to thefirst UE device (1634); operate the first small cell base station (1604)to monitor (2514) for a response to the paging signal transmitted fromthe first small cell base station; and decide (2522), when said themonitoring failed to detect a paging response, to include a pagingfailure indication in the paging response message when generating thepaging response message.

System Embodiment 22 The communications system (1600) of SystemEmbodiment 21, wherein the paging response message indicates that thereason for the paging failure was no response received from the first UEdevice in response to a transmitted paging signal.

System Embodiment 23 The communications system (1600) of SystemEmbodiment 19, wherein said listen before talk operation determines thatthe unlicensed spectrum is unavailable; and wherein the second processor(2702) is further configured to: operate (2524) the first small cellbase station (1608) to determine if either of: i) the maximum time limitfor performing listen before talk (LBT) checks on the unlicensedspectrum for this paging message has been reached, or ii) the pagingmessage exceeded the allowable time for a paging message to be in thebase station buffer, has been satisfied; and; and wherein said secondprocessor (2702) is configured to: include (2541) in the paging responsemessage an indication that the paging attempt to page the UE (1634) wasa failure and that the reason for the failure was that unlicensedspectrum was unavailable, at the first small cell base station (1608),for transmission of a paging signal to the first UE (1634), as part ofbeing configured to generate (2534), at the first small cell basestation (1608), said paging response message.

System Embodiment 24 The communications system (1600) of SystemEmbodiment 19, wherein said listen before talk operation determines thatthe unlicensed spectrum is unavailable; and wherein said secondprocessor (2702) is further configured to: operate (2524) the firstsmall cell base station (1608) to determine if either of: i) the maximumtime limit for performing listen before talk (LBT) checks on theunlicensed spectrum for this paging message has been reached, or ii) thepaging message exceeded the allowable time for a paging message to be inthe base station buffer, has been satisfied; and generate (2540) apaging failure response message which communicates (either explicitly,e.g., via a failure code, or implicitly, e.g., via the presence of thefailure response message) that the paging attempt by the first smallcell base station (1608) to page the first UE (1634) failed and thereason for the paging attempt failure is unavailability of theunlicensed spectrum (LBT fails to clear) resulting in no paging signalto page the first UE (1634) being transmitted by the first small cellbase station (1608), as part of being configured to generate (2534), atthe first small cell base station (1608), said paging response message.

Numbered List of Exemplary Computer Readable Medium Embodiments

Computer Readable Medium Embodiment 1 A non-transitory computer readablemedium (2610) including computer executable instructions which whenexecuted by a processor (2602) control a first base station (2600 or1604) to perform the steps of: receiving (1504), at the first basestation, a paging request to page a first UE device; determining (1506),at the first base station, a first set of base stations which are toattempt to page the first UE device, said first set of base stationsincluding a small cell base station; sending (1532), from the first basestation, a paging request message to the small cell base station in saidfirst set of base stations, said paging request message requestingpaging of the first UE device; and receiving (1542), at the first basestation, a paging response message from the small cell base station,said paging response message indicating one of: i) an attempt at thesmall cell base station to page the first UE device was successful orii) an attempt at the small cell base station to page the first UEdevice was unsuccessful.

Computer Readable Medium Embodiment 2 A non-transitory computer readablemedium (2710) including computer executable instructions which whenexecuted by a processor (2702) control a first small cell base station(2700 or 1608) to perform the steps of: receiving (2504), at the firstsmall cell base station, the said paging request message, sent by themacro base station, requesting paging of the first UE device; andperforming (2508), at the first small cell base station, in response tosaid received paging request message, a listen before talk (LBT)operation to determine if unlicensed spectrum is available to use totransmit a paging signal to the first UE device.

Computer Readable Medium Embodiment 3 The non-transitory computerreadable medium (2710) of Computer Readable Medium Embodiment 2, furthercomprising computer executable instructions which when executed by saidprocessor (2702) control said first small cell base station (2700 or1608) to perform the steps of: generating (2534), at the first smallcell base station, said paging response message indicating one of: i) anattempt at the first small cell base station to page the first UE devicewas successful or ii) an attempt at the first small cell base station topage the first UE device was unsuccessful; and transmitting (2542), atthe first small cell base station, the generated paging response messageto the macro base station.

The techniques of various embodiments may be implemented using software,hardware and/or a combination of software and hardware. Variousembodiments are directed to apparatus, e.g., user devices such as a userequipment (UE) device, base stations (macro cell base stations and smallcell base stations) such as a gNB or ng-eNB, network nodes, an AMFdevice, servers, customer premises equipment devices, cable systems,network nodes, gateways, cable headend/hubsites, network monitoringnode/servers, cluster controllers, cloud nodes, production nodes, cloudservices servers and/or network equipment devices. Various embodimentsare also directed to methods, e.g., method of controlling and/oroperating user devices, base stations, gateways, servers, cablenetworks, cloud networks, nodes, servers, cloud service servers,customer premises equipment devices, controllers, network monitoringnodes/servers and/or cable or network equipment devices. Variousembodiments are also directed to machine, e.g., computer, readablemedium, e.g., ROM, RAM, CDs, hard discs, etc., which include machinereadable instructions for controlling a machine to implement one or moresteps of a method. The computer readable medium is, e.g., non-transitorycomputer readable medium.

It is understood that the specific order or hierarchy of steps in theprocesses and methods disclosed is an example of exemplary approaches.Based upon design preferences, it is understood that the specific orderor hierarchy of steps in the processes and methods may be rearrangedwhile remaining within the scope of the present disclosure. Theaccompanying method claims present elements of the various steps in asample order, and are not meant to be limited to the specific order orhierarchy presented. In some embodiments, one or more processors areused to carry out one or more steps of the each of the describedmethods.

In various embodiments each of the steps or elements of a method areimplemented using one or more processors. In some embodiments, each ofelements are steps are implemented using hardware circuitry.

In various embodiments nodes and/or elements described herein areimplemented using one or more components to perform the stepscorresponding to one or more methods, for example, message reception,signal processing, sending, comparing, determining and/or transmissionsteps. Thus, in some embodiments various features are implemented usingcomponents or in some embodiments logic such as for example logiccircuits. Such components may be implemented using software, hardware ora combination of software and hardware. Many of the above describedmethods or method steps can be implemented using machine executableinstructions, such as software, included in a machine readable mediumsuch as a memory device, e.g., RAM, floppy disk, etc. to control amachine, e.g., general purpose computer with or without additionalhardware, to implement all or portions of the above described methods,e.g., in one or more nodes. Accordingly, among other things, variousembodiments are directed to a machine-readable medium, e.g., anon-transitory computer readable medium, including machine executableinstructions for causing a machine, e.g., processor and associatedhardware, to perform one or more of the steps of the above-describedmethod(s). Some embodiments are directed to a device, e.g., acontroller, including a processor configured to implement one, multipleor all of the steps of one or more methods of the invention.

In some embodiments, the processor or processors, e.g., CPUs, of one ormore devices, e.g., communications nodes such as controllers areconfigured to perform the steps of the methods described as beingperformed by the communications nodes, e.g., controllers. Theconfiguration of the processor may be achieved by using one or morecomponents, e.g., software components, to control processorconfiguration and/or by including hardware in the processor, e.g.,hardware components, to perform the recited steps and/or controlprocessor configuration. Accordingly, some but not all embodiments aredirected to a device, e.g., communications node such as a clustercontroller including, with a processor which includes a componentcorresponding to each of the steps of the various described methodsperformed by the device in which the processor is included. In some butnot all embodiments a device, e.g., communications node such as acontroller, includes a controller corresponding to each of the steps ofthe various described methods performed by the device in which theprocessor is included. The components may be implemented using softwareand/or hardware.

Some embodiments are directed to a computer program product comprising acomputer-readable medium, e.g., a non-transitory computer-readablemedium, comprising code for causing a computer, or multiple computers,to implement various functions, steps, acts and/or operations, e.g. oneor more steps described above. Depending on the embodiment, the computerprogram product can, and sometimes does, include different code for eachstep to be performed. Thus, the computer program product may, andsometimes does, include code for each individual step of a method, e.g.,a method of controlling a controller or node. The code may be in theform of machine, e.g., computer, executable instructions stored on acomputer-readable medium, e.g., a non-transitory computer-readablemedium, such as a RAM (Random Access Memory), ROM (Read Only Memory) orother type of storage device. In addition to being directed to acomputer program product, some embodiments are directed to a processorconfigured to implement one or more of the various functions, steps,acts and/or operations of one or more methods described above.Accordingly, some embodiments are directed to a processor, e.g., CPU,configured to implement some or all of the steps of the methodsdescribed herein. The processor may be for use in, e.g., acommunications device such as a controller or other device described inthe present application. In some embodiments components are implementedas hardware devices in such embodiments the components are hardwarecomponents. In other embodiments components may be implemented assoftware, e.g., a set of processor or computer executable instructions.Depending on the embodiment the components may be all hardwarecomponents, all software components, a combination of hardware and/orsoftware or in some embodiments some components are hardware componentswhile other components are software components.

Numerous additional variations on the methods and apparatus of thevarious embodiments described above will be apparent to those skilled inthe art in view of the above description. Such variations are to beconsidered within the scope. Numerous additional embodiments, within thescope of the present invention, will be apparent to those of ordinaryskill in the art in view of the above description and the claims whichfollow. Such variations are to be considered within the scope of theinvention.

What is claimed is:
 1. A communications method, the method comprising:receiving, at a first base station, a paging request to page a first UEdevice; determining, at the first base station, a first set of basestations which are to attempt to page the first UE device, said firstset of base stations including a small cell base station; sending, fromthe first base station, a paging request message to the small cell basestation in said first set of base stations, said paging request messagerequesting paging of the first UE device; receiving, at the first basestation, a paging response message from the small cell base station,said paging response message indicating one of: i) an attempt at thesmall cell base station to page the first UE device was successful orii) an attempt at the small cell base station to page the first UEdevice was unsuccessful; receiving, at the first base station, anadditional paging request to page the first UE device; determining, atthe first base station, an additional set of base stations which are toattempt to page the first UE device, said additional set of basestations including an additional small cell base station which is notincluded in said first set of base stations; sending, from the firstbase station, a paging request message to the additional small cell basestation in said additional set of base stations, said paging requestmessage to the additional small cell base station requesting paging ofthe first UE device; and receiving, at the first base station, a pagingresponse message from the additional small cell base station, saidpaging response message indicating one of: i) an attempt at theadditional small cell base station to page the first UE device wassuccessful or ii) an attempt at the additional small cell base stationto page the first UE device was unsuccessful.
 2. The communicationsmethod of claim 1, wherein the first base station is a macro basestation; and wherein said small cell base station is a first small cellbase station having a coverage area smaller than the coverage area ofsaid macro base station.
 3. The method of claim 2, wherein determining,at the first base station, the first set of base stations which are toattempt to page the first UE device includes determining the first setof base stations based on one or more of: i) historical cellinformation, ii) first UE mobility pattern information, iii) signalmeasurement reports communicated by the first UE to the first basestation, iv) channel quality information feedback communicated by thefirst UE to the first base station or another network device, v)physical downlink control channel load on a physical downlink controlchannel (PDCCH) at the first base station, vi) a received signalstrength of a signal transmitted by the first base station as reportedto the first base station to by the first UE, vii) a number of UEsrequiring paging, viii) a number of small cells under a coverage area ofthe first base station, ix) radio network planning data or x) receivedUE reports.
 4. The method of claim 2, wherein the paging responsemessage from the first small cell base station indicates a pagingfailure and wherein the paging response message from the first smallcell base station further indicates the reason for the paging attemptfailure.
 5. The method of claim 2, wherein said paging request to page afirst UE device received at the first base station is received from anetwork device; and wherein the method further comprises: sending, fromthe first base station, a paging results message to the network device,said paging results message indicating one of success or failure to pagethe first UE.
 6. The method of claim 2, further comprising: receiving,at the first small cell base station, said paging request message, sentby the macro base station, requesting paging of the first UE device; andperforming, at the first small cell base station, in response to saidreceived paging request message, a listen before talk (LBT) operation todetermine if unlicensed spectrum is available to use to transmit apaging signal to the first UE device.
 7. The method of claim 6, furthercomprising: generating, at the first small cell base station, saidpaging response message indicating one of: i) an attempt at the firstsmall cell base station to page the first UE device was successful orii) an attempt at the first small cell base station to page the first UEdevice was unsuccessful; and transmitting, at the first small cell basestation, the generated paging response message to the macro basestation.
 8. The method of claim 7, wherein said listen before talkoperation determines that the unlicensed spectrum is available; andwherein the method further comprises: transmitting, at the first smallcell base station, a paging signal from the first small cell basestation directed to the first UE device; monitoring, at the first smallcell base station, for a response to the paging signal transmitted fromthe first small cell base station; deciding, at the first small cellbase station, when said the monitoring detected a response, to include apaging success indication in the paging response message when generatingthe paging response message; and deciding, at the first small cell basestation, when said the monitoring failed to detect a response, toinclude a paging failure indication in the paging response message whengenerating the paging response message.
 9. The method of claim 7,wherein said listen before talk operation determines that the unlicensedspectrum is unavailable; and wherein the method further comprises:operating the first small cell base station to determine if either of:i) the maximum time limit for performing listen before talk (LBT) checkson the unlicensed spectrum for this paging message has been reached, orii) the paging message exceeded the allowable time for a paging messageto be in the base station buffer, has been satisfied; and wherein saidstep of generating, at the first small cell base station, said pagingresponse message includes: including in the paging response message anindication that the paging attempt to page the UE was a failure and thatthe reason for the failure was that unlicensed spectrum was unavailable,at the first small cell base station, for transmission of a pagingsignal to the first UE.
 10. A communications method, the methodcomprising: receiving, at a first base station, a paging request to pagea first UE device; determining, at the first base station, a first setof base stations which are to attempt to page the first UE device, saidfirst set of base stations including a small cell base station; sending,from the first base station, a paging request message to the small cellbase station in said first set of base stations, said paging requestmessage requesting paging of the first UE device; receiving, at thefirst base station, a paging response message from the small cell basestation, said paging response message indicating one of: i) an attemptat the small cell base station to page the first UE device wassuccessful or ii) an attempt at the small cell base station to page thefirst UE device was unsuccessful; receiving, at the first base station,a second paging request, said second paging request being a request topage a second UE device; determining, at the first base station, asecond set of base stations which are to attempt to page the second UEdevice, said second set of base stations including a second small cellbase station, said second small cell base station not being in saidfirst set of base stations; sending, from the first base station, apaging request message to the second small cell base station in saidsecond set of base stations, said paging request message requestingpaging of the second UE device; and receiving, at the first basestation, a paging response message from the second small cell basestation, said paging response message indicating one of: i) an attemptat the second small cell base station to page the second UE device wassuccessful or ii) an attempt at the small cell base station to page thesecond UE device was unsuccessful.
 11. The method of claim 10, whereindetermining, at the first base station, the second set of base stationswhich are to attempt to page the second UE device includes determiningthe second set of base stations based on one or more of: i) historicalcell information corresponding to the second UE, ii) second UE mobilitypattern information, iii) signal measurement reports communicated by thesecond UE to the first base station, iv) channel quality informationfeedback communicated by the second UE to the first base station oranother network device, v) physical downlink control channel (PDDCH)load on a physical downlink control channel at the first base station,vi) a received signal strength of a signal transmitted by the first basestation as reported to the first base station by the second UE, vii) thenumber of UEs requiring paging, viii) the number of small cells under acoverage area of the first base station, ix) radio network planning dataor x) received UE reports.
 12. A communications system comprising: afirst base station including: a first processor configured to: operatethe first base station to receive a paging request to page a first UEdevice; determine a first set of base stations which are to attempt topage the first UE device, said first set of base stations including asmall cell base station; operate the first base station to send a pagingrequest message to the small cell base station in said first set of basestations, said paging request message requesting paging of the first UEdevice; operate the first base station to receive a paging responsemessage from the small cell base station, said paging response messageindicating one of: i) an attempt at the small cell base station to pagethe first UE device was successful or ii) an attempt at the small cellbase station to page the first UE device was unsuccessful; operate thefirst base station to receive an additional paging request to page thefirst UE device; determine an additional set of base stations which areto attempt to page the first UE device, said additional set of basestations including an additional small cell base station which is notincluded in said first set of base stations; operate the first basestation to send a paging request message to the additional small cellbase station in said additional set of base stations, said pagingrequest message to the additional small cell base station requestingpaging of the first UE device; and operate the first base station toreceive a paging response message from the additional small cell basestation, said paging response message indicating one of: i) an attemptat the additional small cell base station to page the first UE devicewas successful or ii) an attempt at the additional small cell basestation to page the first UE device was unsuccessful.
 13. Thecommunications system of claim 12, wherein the first base station is amacro base station; and wherein said small cell base station is a firstsmall cell base station having a coverage area smaller than the coveragearea of said macro base station.
 14. The communications system of claim13, wherein said first processor is configured to: determine the firstset of base stations based on one or more of: i) historical cellinformation, ii) first UE mobility pattern information, iii) signalmeasurement reports communicated by the first UE to the first basestation, iv) channel quality information feedback communicated by thefirst UE to the first base station or another network device, v)physical downlink control channel load on a physical downlink controlchannel (PDCCH) at the first base station, vi) a received signalstrength of a signal transmitted by the first base station as reportedto the first base station by the first UE, vii) a number of UEsrequiring paging, viii) a number of small cells under a coverage area ofthe first base station, ix) radio network planning data or x) receivedUE reports, as part of being configured to determine the first set ofbase stations which are to attempt to page the first UE device.
 15. Thecommunications system of claim 13, wherein the paging response messagefrom the first small cell base station indicates a paging failure andwherein the paging response message from the first small cell basestation further indicates the reason for the paging attempt failure. 16.The communications system of claim 13, wherein said paging request topage a first UE device received at the first base station is receivedfrom a network device; and wherein said first processor is furtherconfigured to: operate the first base station to send a paging resultsmessage to the network device, said paging results message indicatingone of success or failure to page the first UE.
 17. The communicationssystem of claim 13, further comprising: said first small cell basestation, said first small cell base station including: a secondprocessor configured to: operate the first small cell base station toreceive said paging request message, sent by the macro cell basestation, requesting paging of the first UE device; and perform, inresponse to said received paging request message, a listen before talk(LBT) operation to determine if unlicensed spectrum is available to useto transmit a paging signal to the first UE device.
 18. Thecommunications system of claim 17, wherein said second processor isfurther configured to: generate said paging response message indicatingone of: i) an attempt at the first small cell base station to page thefirst UE device was successful or ii) an attempt at the first small cellbase station to page the first UE device was unsuccessful; and operatethe first small cell base station to transmit the generated pagingresponse message to the macro cell base station.
 19. A non-transitorycomputer readable medium including computer executable instructionswhich when executed by a processor control a first base station toperform the steps of: receiving, at the first base station, a pagingrequest to page a first UE device; determining, at the first basestation, a first set of base stations which are to attempt to page thefirst UE device, said first set of base stations including a small cellbase station; sending, from the first base station, a paging requestmessage to the small cell base station in said first set of basestations, said paging request message requesting paging of the first UEdevice; receiving, at the first base station, a paging response messagefrom the small cell base station, said paging response messageindicating one of: i) an attempt at the small cell base station to pagethe first UE device was successful or ii) an attempt at the small cellbase station to page the first UE device was unsuccessful; receiving, atthe first base station, an additional paging request to page the firstUE device; determining, at the first base station, an additional set ofbase stations which are to attempt to page the first UE device, saidadditional set of base stations including an additional small cell basestation which is not included in said first set of base stations;sending, from the first base station, a paging request message to theadditional small cell base station in said additional set of basestations, said paging request message to the additional small cell basestation requesting paging of the first UE device; and receiving, at thefirst base station, a paging response message from the additional smallcell base station, said paging response message indicating one of: i) anattempt at the additional small cell base station to page the first UEdevice was successful or ii) an attempt at the additional small cellbase station to page the first UE device was unsuccessful.